==================================================================
BUG: KASAN: slab-use-after-free in snapshot_ctr+0x1c20/0x1fd0 drivers/md/dm-snap.c:1284
Read of size 8 at addr ffff88802bcfec18 by task syz.6.875/10805
CPU: 0 UID: 0 PID: 10805 Comm: syz.6.875 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
snapshot_ctr+0x1c20/0x1fd0 drivers/md/dm-snap.c:1284
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2f8379f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2f84613028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2f83a25fa0 RCX: 00007f2f8379f559
RDX: 0000200000009280 RSI: 00000000c138fd09 RDI: 0000000000000004
RBP: 00007f2f83836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f83a26038 R14: 00007f2f83a25fa0 R15: 00007ffd87aa8278
Allocated by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_node_noprof+0x30c/0x710 mm/slub.c:5699
_kmalloc_node_noprof include/linux/slab.h:1196 [inline]
open_table_device drivers/md/dm.c:733 [inline]
dm_get_table_device+0x2fc/0x820 drivers/md/dm.c:821
dm_get_device+0x525/0x7e0 drivers/md/dm-table.c:388
snapshot_ctr+0x201/0x1fd0 drivers/md/dm-snap.c:1269
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2780 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x22b/0x6d0 mm/slub.c:6923
close_table_device drivers/md/dm.c:798 [inline]
dm_put_table_device+0x2bf/0x380 drivers/md/dm.c:841
upgrade_mode drivers/md/dm-table.c:326 [inline]
dm_get_device+0x3f1/0x7e0 drivers/md/dm-table.c:399
snapshot_ctr+0x326/0x1fd0 drivers/md/dm-snap.c:1279
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802bcfec00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 24 bytes inside of
freed 96-byte region [ffff88802bcfec00, ffff88802bcfec60)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bcfe
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813ff07280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1035, tgid 1035 (kworker/u8:6), ts 7632214243
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1856
prep_new_page mm/page_alloc.c:1864 [inline]
get_page_from_freelist+0x1113/0x35e0 mm/page_alloc.c:3935
__alloc_frozen_pages_noprof+0x2bd/0x3280 mm/page_alloc.c:5444
alloc_slab_page mm/slub.c:3384 [inline]
allocate_slab mm/slub.c:3499 [inline]
new_slab+0xb1/0x6d0 mm/slub.c:3550
refill_objects+0xe3/0x410 mm/slub.c:7539
refill_sheaf mm/slub.c:2917 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
alloc_from_pcs mm/slub.c:4887 [inline]
slab_alloc_node mm/slub.c:5021 [inline]
__do_kmalloc_node mm/slub.c:5530 [inline]
__kmalloc_noprof+0x677/0x840 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
lsm_blob_alloc+0x68/0x90 security/security.c:219
lsm_task_alloc security/security.c:271 [inline]
security_task_alloc+0x2a/0x260 security/security.c:2806
copy_process+0x2c48/0x84c0 kernel/fork.c:2300
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
page last free pid 1035 tgid 1035 ts 7632096222 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1403 [inline]
__free_frozen_pages+0x7b4/0x1110 mm/page_alloc.c:2954
__kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]
__kasan_populate_vmalloc+0x1ea/0x210 mm/kasan/shadow.c:424
kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
alloc_vmap_area+0x963/0x2bc0 mm/vmalloc.c:2151
__get_vm_area_node+0x1ed/0x350 mm/vmalloc.c:3281
__vmalloc_node_range_noprof+0x2ad/0x1440 mm/vmalloc.c:4112
__vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4213
alloc_thread_stack_node kernel/fork.c:359 [inline]
dup_task_struct kernel/fork.c:931 [inline]
copy_process+0x80b/0x84c0 kernel/fork.c:2142
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff88802bcfeb00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfeb80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88802bcfec00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff88802bcfec80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfed00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:650 [inline]
BUG: KASAN: slab-use-after-free in string+0x471/0x4d0 lib/vsprintf.c:732
Read of size 1 at addr ffff88802bcfec34 by task syz.6.875/10805
CPU: 1 UID: 0 PID: 10805 Comm: syz.6.875 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
string_nocheck lib/vsprintf.c:650 [inline]
string+0x471/0x4d0 lib/vsprintf.c:732
vsnprintf+0x422/0x1300 lib/vsprintf.c:2948
vprintk_store+0x3b3/0xbe0 kernel/printk/printk.c:2307
vprintk_emit+0x139/0x6b0 kernel/printk/printk.c:2455
_printk+0xcf/0x110 kernel/printk/printk.c:2504
dm_put_device+0x2fa/0x3a0 drivers/md/dm-table.c:467
snapshot_ctr+0x12ba/0x1fd0 drivers/md/dm-snap.c:1423
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2f8379f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2f84613028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2f83a25fa0 RCX: 00007f2f8379f559
RDX: 0000200000009280 RSI: 00000000c138fd09 RDI: 0000000000000004
RBP: 00007f2f83836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f83a26038 R14: 00007f2f83a25fa0 R15: 00007ffd87aa8278
Allocated by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_node_noprof+0x30c/0x710 mm/slub.c:5699
_kmalloc_node_noprof include/linux/slab.h:1196 [inline]
open_table_device drivers/md/dm.c:733 [inline]
dm_get_table_device+0x2fc/0x820 drivers/md/dm.c:821
dm_get_device+0x525/0x7e0 drivers/md/dm-table.c:388
snapshot_ctr+0x201/0x1fd0 drivers/md/dm-snap.c:1269
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2780 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x22b/0x6d0 mm/slub.c:6923
close_table_device drivers/md/dm.c:798 [inline]
dm_put_table_device+0x2bf/0x380 drivers/md/dm.c:841
upgrade_mode drivers/md/dm-table.c:326 [inline]
dm_get_device+0x3f1/0x7e0 drivers/md/dm-table.c:399
snapshot_ctr+0x326/0x1fd0 drivers/md/dm-snap.c:1279
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802bcfec00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 52 bytes inside of
freed 96-byte region [ffff88802bcfec00, ffff88802bcfec60)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bcfe
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813ff07280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1035, tgid 1035 (kworker/u8:6), ts 7632214243
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1856
prep_new_page mm/page_alloc.c:1864 [inline]
get_page_from_freelist+0x1113/0x35e0 mm/page_alloc.c:3935
__alloc_frozen_pages_noprof+0x2bd/0x3280 mm/page_alloc.c:5444
alloc_slab_page mm/slub.c:3384 [inline]
allocate_slab mm/slub.c:3499 [inline]
new_slab+0xb1/0x6d0 mm/slub.c:3550
refill_objects+0xe3/0x410 mm/slub.c:7539
refill_sheaf mm/slub.c:2917 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
alloc_from_pcs mm/slub.c:4887 [inline]
slab_alloc_node mm/slub.c:5021 [inline]
__do_kmalloc_node mm/slub.c:5530 [inline]
__kmalloc_noprof+0x677/0x840 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
lsm_blob_alloc+0x68/0x90 security/security.c:219
lsm_task_alloc security/security.c:271 [inline]
security_task_alloc+0x2a/0x260 security/security.c:2806
copy_process+0x2c48/0x84c0 kernel/fork.c:2300
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
page last free pid 1035 tgid 1035 ts 7632096222 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1403 [inline]
__free_frozen_pages+0x7b4/0x1110 mm/page_alloc.c:2954
__kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]
__kasan_populate_vmalloc+0x1ea/0x210 mm/kasan/shadow.c:424
kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
alloc_vmap_area+0x963/0x2bc0 mm/vmalloc.c:2151
__get_vm_area_node+0x1ed/0x350 mm/vmalloc.c:3281
__vmalloc_node_range_noprof+0x2ad/0x1440 mm/vmalloc.c:4112
__vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4213
alloc_thread_stack_node kernel/fork.c:359 [inline]
dup_task_struct kernel/fork.c:931 [inline]
copy_process+0x80b/0x84c0 kernel/fork.c:2142
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff88802bcfeb00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfeb80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff88802bcfec00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff88802bcfec80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfed00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:650 [inline]
BUG: KASAN: slab-use-after-free in string+0x471/0x4d0 lib/vsprintf.c:732
Read of size 1 at addr ffff88802bcfec35 by task syz.6.875/10805
CPU: 1 UID: 0 PID: 10805 Comm: syz.6.875 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
string_nocheck lib/vsprintf.c:650 [inline]
string+0x471/0x4d0 lib/vsprintf.c:732
vsnprintf+0x422/0x1300 lib/vsprintf.c:2948
vprintk_store+0x3b3/0xbe0 kernel/printk/printk.c:2307
vprintk_emit+0x139/0x6b0 kernel/printk/printk.c:2455
_printk+0xcf/0x110 kernel/printk/printk.c:2504
dm_put_device+0x2fa/0x3a0 drivers/md/dm-table.c:467
snapshot_ctr+0x12ba/0x1fd0 drivers/md/dm-snap.c:1423
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2f8379f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2f84613028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2f83a25fa0 RCX: 00007f2f8379f559
RDX: 0000200000009280 RSI: 00000000c138fd09 RDI: 0000000000000004
RBP: 00007f2f83836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f83a26038 R14: 00007f2f83a25fa0 R15: 00007ffd87aa8278
Allocated by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_node_noprof+0x30c/0x710 mm/slub.c:5699
_kmalloc_node_noprof include/linux/slab.h:1196 [inline]
open_table_device drivers/md/dm.c:733 [inline]
dm_get_table_device+0x2fc/0x820 drivers/md/dm.c:821
dm_get_device+0x525/0x7e0 drivers/md/dm-table.c:388
snapshot_ctr+0x201/0x1fd0 drivers/md/dm-snap.c:1269
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2780 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x22b/0x6d0 mm/slub.c:6923
close_table_device drivers/md/dm.c:798 [inline]
dm_put_table_device+0x2bf/0x380 drivers/md/dm.c:841
upgrade_mode drivers/md/dm-table.c:326 [inline]
dm_get_device+0x3f1/0x7e0 drivers/md/dm-table.c:399
snapshot_ctr+0x326/0x1fd0 drivers/md/dm-snap.c:1279
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802bcfec00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 53 bytes inside of
freed 96-byte region [ffff88802bcfec00, ffff88802bcfec60)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bcfe
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813ff07280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1035, tgid 1035 (kworker/u8:6), ts 7632214243
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1856
prep_new_page mm/page_alloc.c:1864 [inline]
get_page_from_freelist+0x1113/0x35e0 mm/page_alloc.c:3935
__alloc_frozen_pages_noprof+0x2bd/0x3280 mm/page_alloc.c:5444
alloc_slab_page mm/slub.c:3384 [inline]
allocate_slab mm/slub.c:3499 [inline]
new_slab+0xb1/0x6d0 mm/slub.c:3550
refill_objects+0xe3/0x410 mm/slub.c:7539
refill_sheaf mm/slub.c:2917 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
alloc_from_pcs mm/slub.c:4887 [inline]
slab_alloc_node mm/slub.c:5021 [inline]
__do_kmalloc_node mm/slub.c:5530 [inline]
__kmalloc_noprof+0x677/0x840 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
lsm_blob_alloc+0x68/0x90 security/security.c:219
lsm_task_alloc security/security.c:271 [inline]
security_task_alloc+0x2a/0x260 security/security.c:2806
copy_process+0x2c48/0x84c0 kernel/fork.c:2300
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
page last free pid 1035 tgid 1035 ts 7632096222 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1403 [inline]
__free_frozen_pages+0x7b4/0x1110 mm/page_alloc.c:2954
__kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]
__kasan_populate_vmalloc+0x1ea/0x210 mm/kasan/shadow.c:424
kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
alloc_vmap_area+0x963/0x2bc0 mm/vmalloc.c:2151
__get_vm_area_node+0x1ed/0x350 mm/vmalloc.c:3281
__vmalloc_node_range_noprof+0x2ad/0x1440 mm/vmalloc.c:4112
__vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4213
alloc_thread_stack_node kernel/fork.c:359 [inline]
dup_task_struct kernel/fork.c:931 [inline]
copy_process+0x80b/0x84c0 kernel/fork.c:2142
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff88802bcfeb00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfeb80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff88802bcfec00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff88802bcfec80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfed00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:650 [inline]
BUG: KASAN: slab-use-after-free in string+0x471/0x4d0 lib/vsprintf.c:732
Read of size 1 at addr ffff88802bcfec36 by task syz.6.875/10805
CPU: 1 UID: 0 PID: 10805 Comm: syz.6.875 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
string_nocheck lib/vsprintf.c:650 [inline]
string+0x471/0x4d0 lib/vsprintf.c:732
vsnprintf+0x422/0x1300 lib/vsprintf.c:2948
vprintk_store+0x3b3/0xbe0 kernel/printk/printk.c:2307
vprintk_emit+0x139/0x6b0 kernel/printk/printk.c:2455
_printk+0xcf/0x110 kernel/printk/printk.c:2504
dm_put_device+0x2fa/0x3a0 drivers/md/dm-table.c:467
snapshot_ctr+0x12ba/0x1fd0 drivers/md/dm-snap.c:1423
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2f8379f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2f84613028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2f83a25fa0 RCX: 00007f2f8379f559
RDX: 0000200000009280 RSI: 00000000c138fd09 RDI: 0000000000000004
RBP: 00007f2f83836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f83a26038 R14: 00007f2f83a25fa0 R15: 00007ffd87aa8278
Allocated by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_node_noprof+0x30c/0x710 mm/slub.c:5699
_kmalloc_node_noprof include/linux/slab.h:1196 [inline]
open_table_device drivers/md/dm.c:733 [inline]
dm_get_table_device+0x2fc/0x820 drivers/md/dm.c:821
dm_get_device+0x525/0x7e0 drivers/md/dm-table.c:388
snapshot_ctr+0x201/0x1fd0 drivers/md/dm-snap.c:1269
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2780 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x22b/0x6d0 mm/slub.c:6923
close_table_device drivers/md/dm.c:798 [inline]
dm_put_table_device+0x2bf/0x380 drivers/md/dm.c:841
upgrade_mode drivers/md/dm-table.c:326 [inline]
dm_get_device+0x3f1/0x7e0 drivers/md/dm-table.c:399
snapshot_ctr+0x326/0x1fd0 drivers/md/dm-snap.c:1279
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802bcfec00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 54 bytes inside of
freed 96-byte region [ffff88802bcfec00, ffff88802bcfec60)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bcfe
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813ff07280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1035, tgid 1035 (kworker/u8:6), ts 7632214243
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1856
prep_new_page mm/page_alloc.c:1864 [inline]
get_page_from_freelist+0x1113/0x35e0 mm/page_alloc.c:3935
__alloc_frozen_pages_noprof+0x2bd/0x3280 mm/page_alloc.c:5444
alloc_slab_page mm/slub.c:3384 [inline]
allocate_slab mm/slub.c:3499 [inline]
new_slab+0xb1/0x6d0 mm/slub.c:3550
refill_objects+0xe3/0x410 mm/slub.c:7539
refill_sheaf mm/slub.c:2917 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
alloc_from_pcs mm/slub.c:4887 [inline]
slab_alloc_node mm/slub.c:5021 [inline]
__do_kmalloc_node mm/slub.c:5530 [inline]
__kmalloc_noprof+0x677/0x840 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
lsm_blob_alloc+0x68/0x90 security/security.c:219
lsm_task_alloc security/security.c:271 [inline]
security_task_alloc+0x2a/0x260 security/security.c:2806
copy_process+0x2c48/0x84c0 kernel/fork.c:2300
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
page last free pid 1035 tgid 1035 ts 7632096222 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1403 [inline]
__free_frozen_pages+0x7b4/0x1110 mm/page_alloc.c:2954
__kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]
__kasan_populate_vmalloc+0x1ea/0x210 mm/kasan/shadow.c:424
kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
alloc_vmap_area+0x963/0x2bc0 mm/vmalloc.c:2151
__get_vm_area_node+0x1ed/0x350 mm/vmalloc.c:3281
__vmalloc_node_range_noprof+0x2ad/0x1440 mm/vmalloc.c:4112
__vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4213
alloc_thread_stack_node kernel/fork.c:359 [inline]
dup_task_struct kernel/fork.c:931 [inline]
copy_process+0x80b/0x84c0 kernel/fork.c:2142
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff88802bcfeb00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfeb80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff88802bcfec00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff88802bcfec80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfed00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:650 [inline]
BUG: KASAN: slab-use-after-free in string+0x471/0x4d0 lib/vsprintf.c:732
Read of size 1 at addr ffff88802bcfec37 by task syz.6.875/10805
CPU: 1 UID: 0 PID: 10805 Comm: syz.6.875 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
string_nocheck lib/vsprintf.c:650 [inline]
string+0x471/0x4d0 lib/vsprintf.c:732
vsnprintf+0x422/0x1300 lib/vsprintf.c:2948
vprintk_store+0x3b3/0xbe0 kernel/printk/printk.c:2307
vprintk_emit+0x139/0x6b0 kernel/printk/printk.c:2455
_printk+0xcf/0x110 kernel/printk/printk.c:2504
dm_put_device+0x2fa/0x3a0 drivers/md/dm-table.c:467
snapshot_ctr+0x12ba/0x1fd0 drivers/md/dm-snap.c:1423
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2f8379f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2f84613028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2f83a25fa0 RCX: 00007f2f8379f559
RDX: 0000200000009280 RSI: 00000000c138fd09 RDI: 0000000000000004
RBP: 00007f2f83836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f83a26038 R14: 00007f2f83a25fa0 R15: 00007ffd87aa8278
Allocated by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_node_noprof+0x30c/0x710 mm/slub.c:5699
_kmalloc_node_noprof include/linux/slab.h:1196 [inline]
open_table_device drivers/md/dm.c:733 [inline]
dm_get_table_device+0x2fc/0x820 drivers/md/dm.c:821
dm_get_device+0x525/0x7e0 drivers/md/dm-table.c:388
snapshot_ctr+0x201/0x1fd0 drivers/md/dm-snap.c:1269
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2780 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x22b/0x6d0 mm/slub.c:6923
close_table_device drivers/md/dm.c:798 [inline]
dm_put_table_device+0x2bf/0x380 drivers/md/dm.c:841
upgrade_mode drivers/md/dm-table.c:326 [inline]
dm_get_device+0x3f1/0x7e0 drivers/md/dm-table.c:399
snapshot_ctr+0x326/0x1fd0 drivers/md/dm-snap.c:1279
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802bcfec00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 55 bytes inside of
freed 96-byte region [ffff88802bcfec00, ffff88802bcfec60)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bcfe
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813ff07280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1035, tgid 1035 (kworker/u8:6), ts 7632214243
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1856
prep_new_page mm/page_alloc.c:1864 [inline]
get_page_from_freelist+0x1113/0x35e0 mm/page_alloc.c:3935
__alloc_frozen_pages_noprof+0x2bd/0x3280 mm/page_alloc.c:5444
alloc_slab_page mm/slub.c:3384 [inline]
allocate_slab mm/slub.c:3499 [inline]
new_slab+0xb1/0x6d0 mm/slub.c:3550
refill_objects+0xe3/0x410 mm/slub.c:7539
refill_sheaf mm/slub.c:2917 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
alloc_from_pcs mm/slub.c:4887 [inline]
slab_alloc_node mm/slub.c:5021 [inline]
__do_kmalloc_node mm/slub.c:5530 [inline]
__kmalloc_noprof+0x677/0x840 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
lsm_blob_alloc+0x68/0x90 security/security.c:219
lsm_task_alloc security/security.c:271 [inline]
security_task_alloc+0x2a/0x260 security/security.c:2806
copy_process+0x2c48/0x84c0 kernel/fork.c:2300
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
page last free pid 1035 tgid 1035 ts 7632096222 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1403 [inline]
__free_frozen_pages+0x7b4/0x1110 mm/page_alloc.c:2954
__kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]
__kasan_populate_vmalloc+0x1ea/0x210 mm/kasan/shadow.c:424
kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
alloc_vmap_area+0x963/0x2bc0 mm/vmalloc.c:2151
__get_vm_area_node+0x1ed/0x350 mm/vmalloc.c:3281
__vmalloc_node_range_noprof+0x2ad/0x1440 mm/vmalloc.c:4112
__vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4213
alloc_thread_stack_node kernel/fork.c:359 [inline]
dup_task_struct kernel/fork.c:931 [inline]
copy_process+0x80b/0x84c0 kernel/fork.c:2142
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff88802bcfeb00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfeb80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff88802bcfec00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff88802bcfec80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfed00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:650 [inline]
BUG: KASAN: slab-use-after-free in string+0x471/0x4d0 lib/vsprintf.c:732
Read of size 1 at addr ffff88802bcfec38 by task syz.6.875/10805
CPU: 1 UID: 0 PID: 10805 Comm: syz.6.875 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
string_nocheck lib/vsprintf.c:650 [inline]
string+0x471/0x4d0 lib/vsprintf.c:732
vsnprintf+0x422/0x1300 lib/vsprintf.c:2948
vprintk_store+0x3b3/0xbe0 kernel/printk/printk.c:2307
vprintk_emit+0x139/0x6b0 kernel/printk/printk.c:2455
_printk+0xcf/0x110 kernel/printk/printk.c:2504
dm_put_device+0x2fa/0x3a0 drivers/md/dm-table.c:467
snapshot_ctr+0x12ba/0x1fd0 drivers/md/dm-snap.c:1423
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2f8379f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2f84613028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2f83a25fa0 RCX: 00007f2f8379f559
RDX: 0000200000009280 RSI: 00000000c138fd09 RDI: 0000000000000004
RBP: 00007f2f83836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f83a26038 R14: 00007f2f83a25fa0 R15: 00007ffd87aa8278
Allocated by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_node_noprof+0x30c/0x710 mm/slub.c:5699
_kmalloc_node_noprof include/linux/slab.h:1196 [inline]
open_table_device drivers/md/dm.c:733 [inline]
dm_get_table_device+0x2fc/0x820 drivers/md/dm.c:821
dm_get_device+0x525/0x7e0 drivers/md/dm-table.c:388
snapshot_ctr+0x201/0x1fd0 drivers/md/dm-snap.c:1269
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2780 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x22b/0x6d0 mm/slub.c:6923
close_table_device drivers/md/dm.c:798 [inline]
dm_put_table_device+0x2bf/0x380 drivers/md/dm.c:841
upgrade_mode drivers/md/dm-table.c:326 [inline]
dm_get_device+0x3f1/0x7e0 drivers/md/dm-table.c:399
snapshot_ctr+0x326/0x1fd0 drivers/md/dm-snap.c:1279
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802bcfec00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 56 bytes inside of
freed 96-byte region [ffff88802bcfec00, ffff88802bcfec60)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bcfe
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813ff07280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1035, tgid 1035 (kworker/u8:6), ts 7632214243
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1856
prep_new_page mm/page_alloc.c:1864 [inline]
get_page_from_freelist+0x1113/0x35e0 mm/page_alloc.c:3935
__alloc_frozen_pages_noprof+0x2bd/0x3280 mm/page_alloc.c:5444
alloc_slab_page mm/slub.c:3384 [inline]
allocate_slab mm/slub.c:3499 [inline]
new_slab+0xb1/0x6d0 mm/slub.c:3550
refill_objects+0xe3/0x410 mm/slub.c:7539
refill_sheaf mm/slub.c:2917 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
alloc_from_pcs mm/slub.c:4887 [inline]
slab_alloc_node mm/slub.c:5021 [inline]
__do_kmalloc_node mm/slub.c:5530 [inline]
__kmalloc_noprof+0x677/0x840 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
lsm_blob_alloc+0x68/0x90 security/security.c:219
lsm_task_alloc security/security.c:271 [inline]
security_task_alloc+0x2a/0x260 security/security.c:2806
copy_process+0x2c48/0x84c0 kernel/fork.c:2300
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
page last free pid 1035 tgid 1035 ts 7632096222 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1403 [inline]
__free_frozen_pages+0x7b4/0x1110 mm/page_alloc.c:2954
__kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]
__kasan_populate_vmalloc+0x1ea/0x210 mm/kasan/shadow.c:424
kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
alloc_vmap_area+0x963/0x2bc0 mm/vmalloc.c:2151
__get_vm_area_node+0x1ed/0x350 mm/vmalloc.c:3281
__vmalloc_node_range_noprof+0x2ad/0x1440 mm/vmalloc.c:4112
__vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4213
alloc_thread_stack_node kernel/fork.c:359 [inline]
dup_task_struct kernel/fork.c:931 [inline]
copy_process+0x80b/0x84c0 kernel/fork.c:2142
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff88802bcfeb00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfeb80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff88802bcfec00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff88802bcfec80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfed00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
==================================================================
device-mapper: table: 248:0: device 1:12 not in table devices list
==================================================================
BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:650 [inline]
BUG: KASAN: slab-use-after-free in string+0x471/0x4d0 lib/vsprintf.c:732
Read of size 1 at addr ffff88802bcfec34 by task syz.6.875/10805
CPU: 1 UID: 0 PID: 10805 Comm: syz.6.875 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
string_nocheck lib/vsprintf.c:650 [inline]
string+0x471/0x4d0 lib/vsprintf.c:732
vsnprintf+0x422/0x1300 lib/vsprintf.c:2948
vscnprintf+0x40/0x90 lib/vsprintf.c:3017
printk_sprint+0x31/0x330 kernel/printk/printk.c:2222
vprintk_store+0x507/0xbe0 kernel/printk/printk.c:2364
vprintk_emit+0x139/0x6b0 kernel/printk/printk.c:2455
_printk+0xcf/0x110 kernel/printk/printk.c:2504
dm_put_device+0x2fa/0x3a0 drivers/md/dm-table.c:467
snapshot_ctr+0x12ba/0x1fd0 drivers/md/dm-snap.c:1423
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2f8379f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2f84613028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2f83a25fa0 RCX: 00007f2f8379f559
RDX: 0000200000009280 RSI: 00000000c138fd09 RDI: 0000000000000004
RBP: 00007f2f83836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f83a26038 R14: 00007f2f83a25fa0 R15: 00007ffd87aa8278
Allocated by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_node_noprof+0x30c/0x710 mm/slub.c:5699
_kmalloc_node_noprof include/linux/slab.h:1196 [inline]
open_table_device drivers/md/dm.c:733 [inline]
dm_get_table_device+0x2fc/0x820 drivers/md/dm.c:821
dm_get_device+0x525/0x7e0 drivers/md/dm-table.c:388
snapshot_ctr+0x201/0x1fd0 drivers/md/dm-snap.c:1269
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2780 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x22b/0x6d0 mm/slub.c:6923
close_table_device drivers/md/dm.c:798 [inline]
dm_put_table_device+0x2bf/0x380 drivers/md/dm.c:841
upgrade_mode drivers/md/dm-table.c:326 [inline]
dm_get_device+0x3f1/0x7e0 drivers/md/dm-table.c:399
snapshot_ctr+0x326/0x1fd0 drivers/md/dm-snap.c:1279
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802bcfec00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 52 bytes inside of
freed 96-byte region [ffff88802bcfec00, ffff88802bcfec60)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bcfe
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813ff07280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1035, tgid 1035 (kworker/u8:6), ts 7632214243
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1856
prep_new_page mm/page_alloc.c:1864 [inline]
get_page_from_freelist+0x1113/0x35e0 mm/page_alloc.c:3935
__alloc_frozen_pages_noprof+0x2bd/0x3280 mm/page_alloc.c:5444
alloc_slab_page mm/slub.c:3384 [inline]
allocate_slab mm/slub.c:3499 [inline]
new_slab+0xb1/0x6d0 mm/slub.c:3550
refill_objects+0xe3/0x410 mm/slub.c:7539
refill_sheaf mm/slub.c:2917 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
alloc_from_pcs mm/slub.c:4887 [inline]
slab_alloc_node mm/slub.c:5021 [inline]
__do_kmalloc_node mm/slub.c:5530 [inline]
__kmalloc_noprof+0x677/0x840 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
lsm_blob_alloc+0x68/0x90 security/security.c:219
lsm_task_alloc security/security.c:271 [inline]
security_task_alloc+0x2a/0x260 security/security.c:2806
copy_process+0x2c48/0x84c0 kernel/fork.c:2300
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
page last free pid 1035 tgid 1035 ts 7632096222 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1403 [inline]
__free_frozen_pages+0x7b4/0x1110 mm/page_alloc.c:2954
__kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]
__kasan_populate_vmalloc+0x1ea/0x210 mm/kasan/shadow.c:424
kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
alloc_vmap_area+0x963/0x2bc0 mm/vmalloc.c:2151
__get_vm_area_node+0x1ed/0x350 mm/vmalloc.c:3281
__vmalloc_node_range_noprof+0x2ad/0x1440 mm/vmalloc.c:4112
__vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4213
alloc_thread_stack_node kernel/fork.c:359 [inline]
dup_task_struct kernel/fork.c:931 [inline]
copy_process+0x80b/0x84c0 kernel/fork.c:2142
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff88802bcfeb00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfeb80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff88802bcfec00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff88802bcfec80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfed00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:650 [inline]
BUG: KASAN: slab-use-after-free in string+0x471/0x4d0 lib/vsprintf.c:732
Read of size 1 at addr ffff88802bcfec35 by task syz.6.875/10805
CPU: 1 UID: 0 PID: 10805 Comm: syz.6.875 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
string_nocheck lib/vsprintf.c:650 [inline]
string+0x471/0x4d0 lib/vsprintf.c:732
vsnprintf+0x422/0x1300 lib/vsprintf.c:2948
vscnprintf+0x40/0x90 lib/vsprintf.c:3017
printk_sprint+0x31/0x330 kernel/printk/printk.c:2222
vprintk_store+0x507/0xbe0 kernel/printk/printk.c:2364
vprintk_emit+0x139/0x6b0 kernel/printk/printk.c:2455
_printk+0xcf/0x110 kernel/printk/printk.c:2504
dm_put_device+0x2fa/0x3a0 drivers/md/dm-table.c:467
snapshot_ctr+0x12ba/0x1fd0 drivers/md/dm-snap.c:1423
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2f8379f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2f84613028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2f83a25fa0 RCX: 00007f2f8379f559
RDX: 0000200000009280 RSI: 00000000c138fd09 RDI: 0000000000000004
RBP: 00007f2f83836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f83a26038 R14: 00007f2f83a25fa0 R15: 00007ffd87aa8278
Allocated by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_node_noprof+0x30c/0x710 mm/slub.c:5699
_kmalloc_node_noprof include/linux/slab.h:1196 [inline]
open_table_device drivers/md/dm.c:733 [inline]
dm_get_table_device+0x2fc/0x820 drivers/md/dm.c:821
dm_get_device+0x525/0x7e0 drivers/md/dm-table.c:388
snapshot_ctr+0x201/0x1fd0 drivers/md/dm-snap.c:1269
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2780 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x22b/0x6d0 mm/slub.c:6923
close_table_device drivers/md/dm.c:798 [inline]
dm_put_table_device+0x2bf/0x380 drivers/md/dm.c:841
upgrade_mode drivers/md/dm-table.c:326 [inline]
dm_get_device+0x3f1/0x7e0 drivers/md/dm-table.c:399
snapshot_ctr+0x326/0x1fd0 drivers/md/dm-snap.c:1279
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802bcfec00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 53 bytes inside of
freed 96-byte region [ffff88802bcfec00, ffff88802bcfec60)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bcfe
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813ff07280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1035, tgid 1035 (kworker/u8:6), ts 7632214243
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1856
prep_new_page mm/page_alloc.c:1864 [inline]
get_page_from_freelist+0x1113/0x35e0 mm/page_alloc.c:3935
__alloc_frozen_pages_noprof+0x2bd/0x3280 mm/page_alloc.c:5444
alloc_slab_page mm/slub.c:3384 [inline]
allocate_slab mm/slub.c:3499 [inline]
new_slab+0xb1/0x6d0 mm/slub.c:3550
refill_objects+0xe3/0x410 mm/slub.c:7539
refill_sheaf mm/slub.c:2917 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
alloc_from_pcs mm/slub.c:4887 [inline]
slab_alloc_node mm/slub.c:5021 [inline]
__do_kmalloc_node mm/slub.c:5530 [inline]
__kmalloc_noprof+0x677/0x840 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
lsm_blob_alloc+0x68/0x90 security/security.c:219
lsm_task_alloc security/security.c:271 [inline]
security_task_alloc+0x2a/0x260 security/security.c:2806
copy_process+0x2c48/0x84c0 kernel/fork.c:2300
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
page last free pid 1035 tgid 1035 ts 7632096222 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1403 [inline]
__free_frozen_pages+0x7b4/0x1110 mm/page_alloc.c:2954
__kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]
__kasan_populate_vmalloc+0x1ea/0x210 mm/kasan/shadow.c:424
kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
alloc_vmap_area+0x963/0x2bc0 mm/vmalloc.c:2151
__get_vm_area_node+0x1ed/0x350 mm/vmalloc.c:3281
__vmalloc_node_range_noprof+0x2ad/0x1440 mm/vmalloc.c:4112
__vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4213
alloc_thread_stack_node kernel/fork.c:359 [inline]
dup_task_struct kernel/fork.c:931 [inline]
copy_process+0x80b/0x84c0 kernel/fork.c:2142
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff88802bcfeb00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfeb80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff88802bcfec00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff88802bcfec80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfed00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:650 [inline]
BUG: KASAN: slab-use-after-free in string+0x471/0x4d0 lib/vsprintf.c:732
Read of size 1 at addr ffff88802bcfec36 by task syz.6.875/10805
CPU: 1 UID: 0 PID: 10805 Comm: syz.6.875 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
string_nocheck lib/vsprintf.c:650 [inline]
string+0x471/0x4d0 lib/vsprintf.c:732
vsnprintf+0x422/0x1300 lib/vsprintf.c:2948
vscnprintf+0x40/0x90 lib/vsprintf.c:3017
printk_sprint+0x31/0x330 kernel/printk/printk.c:2222
vprintk_store+0x507/0xbe0 kernel/printk/printk.c:2364
vprintk_emit+0x139/0x6b0 kernel/printk/printk.c:2455
_printk+0xcf/0x110 kernel/printk/printk.c:2504
dm_put_device+0x2fa/0x3a0 drivers/md/dm-table.c:467
snapshot_ctr+0x12ba/0x1fd0 drivers/md/dm-snap.c:1423
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2f8379f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2f84613028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2f83a25fa0 RCX: 00007f2f8379f559
RDX: 0000200000009280 RSI: 00000000c138fd09 RDI: 0000000000000004
RBP: 00007f2f83836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f83a26038 R14: 00007f2f83a25fa0 R15: 00007ffd87aa8278
Allocated by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_node_noprof+0x30c/0x710 mm/slub.c:5699
_kmalloc_node_noprof include/linux/slab.h:1196 [inline]
open_table_device drivers/md/dm.c:733 [inline]
dm_get_table_device+0x2fc/0x820 drivers/md/dm.c:821
dm_get_device+0x525/0x7e0 drivers/md/dm-table.c:388
snapshot_ctr+0x201/0x1fd0 drivers/md/dm-snap.c:1269
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2780 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x22b/0x6d0 mm/slub.c:6923
close_table_device drivers/md/dm.c:798 [inline]
dm_put_table_device+0x2bf/0x380 drivers/md/dm.c:841
upgrade_mode drivers/md/dm-table.c:326 [inline]
dm_get_device+0x3f1/0x7e0 drivers/md/dm-table.c:399
snapshot_ctr+0x326/0x1fd0 drivers/md/dm-snap.c:1279
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802bcfec00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 54 bytes inside of
freed 96-byte region [ffff88802bcfec00, ffff88802bcfec60)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bcfe
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813ff07280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1035, tgid 1035 (kworker/u8:6), ts 7632214243
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1856
prep_new_page mm/page_alloc.c:1864 [inline]
get_page_from_freelist+0x1113/0x35e0 mm/page_alloc.c:3935
__alloc_frozen_pages_noprof+0x2bd/0x3280 mm/page_alloc.c:5444
alloc_slab_page mm/slub.c:3384 [inline]
allocate_slab mm/slub.c:3499 [inline]
new_slab+0xb1/0x6d0 mm/slub.c:3550
refill_objects+0xe3/0x410 mm/slub.c:7539
refill_sheaf mm/slub.c:2917 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
alloc_from_pcs mm/slub.c:4887 [inline]
slab_alloc_node mm/slub.c:5021 [inline]
__do_kmalloc_node mm/slub.c:5530 [inline]
__kmalloc_noprof+0x677/0x840 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
lsm_blob_alloc+0x68/0x90 security/security.c:219
lsm_task_alloc security/security.c:271 [inline]
security_task_alloc+0x2a/0x260 security/security.c:2806
copy_process+0x2c48/0x84c0 kernel/fork.c:2300
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
page last free pid 1035 tgid 1035 ts 7632096222 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1403 [inline]
__free_frozen_pages+0x7b4/0x1110 mm/page_alloc.c:2954
__kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]
__kasan_populate_vmalloc+0x1ea/0x210 mm/kasan/shadow.c:424
kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
alloc_vmap_area+0x963/0x2bc0 mm/vmalloc.c:2151
__get_vm_area_node+0x1ed/0x350 mm/vmalloc.c:3281
__vmalloc_node_range_noprof+0x2ad/0x1440 mm/vmalloc.c:4112
__vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4213
alloc_thread_stack_node kernel/fork.c:359 [inline]
dup_task_struct kernel/fork.c:931 [inline]
copy_process+0x80b/0x84c0 kernel/fork.c:2142
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff88802bcfeb00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfeb80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff88802bcfec00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff88802bcfec80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
ffff88802bcfed00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:650 [inline]
BUG: KASAN: slab-use-after-free in string+0x471/0x4d0 lib/vsprintf.c:732
Read of size 1 at addr ffff88802bcfec37 by task syz.6.875/10805
CPU: 1 UID: 0 PID: 10805 Comm: syz.6.875 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
string_nocheck lib/vsprintf.c:650 [inline]
string+0x471/0x4d0 lib/vsprintf.c:732
vsnprintf+0x422/0x1300 lib/vsprintf.c:2948
vscnprintf+0x40/0x90 lib/vsprintf.c:3017
printk_sprint+0x31/0x330 kernel/printk/printk.c:2222
vprintk_store+0x507/0xbe0 kernel/printk/printk.c:2364
vprintk_emit+0x139/0x6b0 kernel/printk/printk.c:2455
_printk+0xcf/0x110 kernel/printk/printk.c:2504
dm_put_device+0x2fa/0x3a0 drivers/md/dm-table.c:467
snapshot_ctr+0x12ba/0x1fd0 drivers/md/dm-snap.c:1423
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2f8379f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2f84613028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2f83a25fa0 RCX: 00007f2f8379f559
RDX: 0000200000009280 RSI: 00000000c138fd09 RDI: 0000000000000004
RBP: 00007f2f83836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f83a26038 R14: 00007f2f83a25fa0 R15: 00007ffd87aa8278
Allocated by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_node_noprof+0x30c/0x710 mm/slub.c:5699
_kmalloc_node_noprof include/linux/slab.h:1196 [inline]
open_table_device drivers/md/dm.c:733 [inline]
dm_get_table_device+0x2fc/0x820 drivers/md/dm.c:821
dm_get_device+0x525/0x7e0 drivers/md/dm-table.c:388
snapshot_ctr+0x201/0x1fd0 drivers/md/dm-snap.c:1269
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 10805:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2780 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x22b/0x6d0 mm/slub.c:6923
close_table_device drivers/md/dm.c:798 [inline]
dm_put_table_device+0x2bf/0x380 drivers/md/dm.c:841
upgrade_mode drivers/md/dm-table.c:326 [inline]
dm_get_device+0x3f1/0x7e0 drivers/md/dm-table.c:399
snapshot_ctr+0x326/0x1fd0 drivers/md/dm-snap.c:1279
dm_table_add_target+0x58b/0xee0 drivers/md/dm-table.c:749
populate_table drivers/md/dm-ioctl.c:1602 [inline]
table_load+0x3b9/0x7b0 drivers/md/dm-ioctl.c:1645
ctl_ioctl+0x4d2/0xcc0 drivers/md/dm-ioctl.c:2221
dm_ctl_ioctl+0x22/0x30 drivers/md/dm-ioctl.c:2243
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802bcfec00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 55 bytes inside of
freed 96-byte region [ffff88802bcfec00, ffff88802bcfec60)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bcfe
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813ff07280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1035, tgid 1035 (kworker/u8:6), ts 7632214243
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1856
prep_new_page mm/page_alloc.c:1864 [inline]
get_page_from_freelist+0x1113/0x35e0 mm/page_alloc.c:3935
__alloc_frozen_pages_noprof+0x2bd/0x3280 mm/page_alloc.c:5444
alloc_slab_page mm/slub.c:3384 [inline]
allocate_slab mm/slub.c:3499 [inline]
new_slab+0xb1/0x6d0 mm/slub.c:3550
refill_objects+0xe3/0x410 mm/slub.c:7539
refill_sheaf mm/slub.c:2917 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
alloc_from_pcs mm/slub.c:4887 [inline]
slab_alloc_node mm/slub.c:5021 [inline]
__do_kmalloc_node mm/slub.c:5530 [inline]
__kmalloc_noprof+0x677/0x840 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
lsm_blob_alloc+0x68/0x90 security/security.c:219
lsm_task_alloc security/security.c:271 [inline]
security_task_alloc+0x2a/0x260 security/security.c:2806
copy_process+0x2c48/0x84c0 kernel/fork.c:2300
kernel_clone+0x176/0x9d0 kernel/fork.c:2784
user_mode_thread+0xd1/0x120 kernel/fork.c:2861
call_usermodehelper_exec_work kernel/umh.c:169 [inline]
call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:155
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659