EXT4-fs (loop2): unmounting filesystem.
==================================================================
BUG: KASAN: use-after-free in fast_dput+0x1e0/0x290 fs/dcache.c:778
Read of size 4 at addr ffff888118088dd0 by task syz-executor/290
CPU: 0 PID: 290 Comm: syz-executor Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
__dump_stack+0x21/0x24 lib/dump_stack.c:88
dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
print_address_description+0x71/0x200 mm/kasan/report.c:316
print_report+0x4a/0x60 mm/kasan/report.c:420
kasan_report+0x122/0x150 mm/kasan/report.c:524
__asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350
fast_dput+0x1e0/0x290 fs/dcache.c:778
dput+0x21/0x80 fs/dcache.c:905
incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166
incfs_kill_sb+0x1af/0x210 fs/incfs/vfs.c:2003
deactivate_locked_super+0xb5/0x120 fs/super.c:336
deactivate_super+0xaf/0xe0 fs/super.c:367
cleanup_mnt+0x45e/0x4e0 fs/namespace.c:1192
__cleanup_mnt+0x19/0x20 fs/namespace.c:1199
task_work_run+0x1e1/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa7c/0x27c0 kernel/exit.c:886
do_group_exit+0x21b/0x2e0 kernel/exit.c:1029
__do_sys_exit_group kernel/exit.c:1040 [inline]
__se_sys_exit_group kernel/exit.c:1038 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1038
x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f87b019ce59
Code: Unable to access opcode bytes at 0x7f87b019ce2f.
RSP: 002b:00007ffdef8d40f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f87b023222a RCX: 00007f87b019ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f87b02321ca
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdef8d53b0
R13: 00007f87b02321ca R14: 00005555825bb4e8 R15: 00007ffdef8d6480
Allocated by task 1059:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505
__kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:334
kasan_slab_alloc include/linux/kasan.h:202 [inline]
slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768
slab_alloc_node mm/slub.c:3382 [inline]
slab_alloc mm/slub.c:3392 [inline]
__kmem_cache_alloc_lru mm/slub.c:3399 [inline]
kmem_cache_alloc_lru+0x104/0x280 mm/slub.c:3415
__d_alloc+0x34/0x6d0 fs/dcache.c:1774
d_alloc fs/dcache.c:1854 [inline]
d_alloc_parallel+0xe2/0x1280 fs/dcache.c:2647
__lookup_slow+0x14f/0x410 fs/namei.c:1682
lookup_one_len+0x19d/0x2e0 fs/namei.c:2747
incfs_lookup_dentry+0x60/0xb0 fs/incfs/data_mgmt.c:210
open_or_create_special_dir+0x4c/0x1f0 fs/incfs/vfs.c:475
incfs_mount_fs+0x42f/0x890 fs/incfs/vfs.c:1890
legacy_get_tree+0xfe/0x1a0 fs/fs_context.c:632
vfs_get_tree+0x9a/0x270 fs/super.c:1578
do_new_mount+0x251/0xb40 fs/namespace.c:3081
path_mount+0x640/0xfd0 fs/namespace.c:3411
do_mount fs/namespace.c:3424 [inline]
__do_sys_mount fs/namespace.c:3632 [inline]
__se_sys_mount+0x320/0x390 fs/namespace.c:3609
__x64_sys_mount+0xbf/0xd0 fs/namespace.c:3609
x64_sys_call+0x65d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Freed by task 13:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516
____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242
__kasan_slab_free+0x11/0x20 mm/kasan/common.c:250
kasan_slab_free include/linux/kasan.h:178 [inline]
slab_free_hook mm/slub.c:1750 [inline]
slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776
slab_free mm/slub.c:3712 [inline]
kmem_cache_free+0x12d/0x300 mm/slub.c:3737
__d_free+0x23/0x30 fs/dcache.c:298
rcu_do_batch+0x52b/0xc30 kernel/rcu/tree.c:2297
rcu_core+0x486/0xf00 kernel/rcu/tree.c:2557
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2574
handle_softirqs+0x1d7/0x600 kernel/softirq.c:642
run_ksoftirqd+0x28/0x30 kernel/softirq.c:1019
smpboot_thread_fn+0x48c/0x8e0 kernel/smpboot.c:164
kthread+0x281/0x320 kernel/kthread.c:386
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Last potentially related work creation:
kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486
kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
__call_rcu_common kernel/rcu/tree.c:2807 [inline]
call_rcu+0xcf/0xf50 kernel/rcu/tree.c:2926
dentry_free+0xbd/0x150 fs/dcache.c:-1
__dentry_kill+0x535/0x680 fs/dcache.c:625
dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
dput+0x42/0x80 fs/dcache.c:918
incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166
incfs_kill_sb+0x1af/0x210 fs/incfs/vfs.c:2003
deactivate_locked_super+0xb5/0x120 fs/super.c:336
deactivate_super+0xaf/0xe0 fs/super.c:367
cleanup_mnt+0x45e/0x4e0 fs/namespace.c:1192
__cleanup_mnt+0x19/0x20 fs/namespace.c:1199
task_work_run+0x1e1/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa7c/0x27c0 kernel/exit.c:886
do_group_exit+0x21b/0x2e0 kernel/exit.c:1029
__do_sys_exit_group kernel/exit.c:1040 [inline]
__se_sys_exit_group kernel/exit.c:1038 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1038
x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Second to last potentially related work creation:
kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486
kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
__call_rcu_common kernel/rcu/tree.c:2807 [inline]
call_rcu+0xcf/0xf50 kernel/rcu/tree.c:2926
dentry_free+0xbd/0x150 fs/dcache.c:-1
__dentry_kill+0x535/0x680 fs/dcache.c:625
dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
dput+0x42/0x80 fs/dcache.c:918
handle_mounts fs/namei.c:1558 [inline]
step_into+0xa02/0xf00 fs/namei.c:1843
walk_component+0x245/0x430 fs/namei.c:2011
lookup_last fs/namei.c:2462 [inline]
path_lookupat+0x155/0x430 fs/namei.c:2486
filename_lookup+0x229/0x580 fs/namei.c:2515
vfs_statx+0x11b/0x6b0 fs/stat.c:229
vfs_fstatat fs/stat.c:267 [inline]
__do_sys_newfstatat fs/stat.c:437 [inline]
__se_sys_newfstatat+0x142/0x440 fs/stat.c:431
__x64_sys_newfstatat+0x9b/0xb0 fs/stat.c:431
x64_sys_call+0x77c/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:263
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
The buggy address belongs to the object at ffff888118088dd0
which belongs to the cache dentry of size 208
The buggy address is located 0 bytes inside of
208-byte region [ffff888118088dd0, ffff888118088ea0)
The buggy address belongs to the physical page:
page:ffffea0004602200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x118088
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 ffffea0004463f40 dead000000000003 ffff8881001edc80
raw: 0000000000000000 00000000000f000f 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Reclaimable, gfp_mask 0x12cd0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_RECLAIMABLE), pid 112, tgid 112 (udevd), ts 4573560068, free_ts 0
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2672
prep_new_page+0x1c/0x110 mm/page_alloc.c:2679
get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4586
__alloc_pages+0x1fa/0x610 mm/page_alloc.c:5930
alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
allocate_slab mm/slub.c:1967 [inline]
new_slab+0x98/0x3e0 mm/slub.c:2020
___slab_alloc+0x70f/0xb70 mm/slub.c:3177
__slab_alloc+0x5e/0xa0 mm/slub.c:3263
slab_alloc_node mm/slub.c:3348 [inline]
slab_alloc mm/slub.c:3392 [inline]
__kmem_cache_alloc_lru mm/slub.c:3399 [inline]
kmem_cache_alloc_lru+0x144/0x280 mm/slub.c:3415
__d_alloc+0x34/0x6d0 fs/dcache.c:1774
d_alloc fs/dcache.c:1854 [inline]
d_alloc_parallel+0xe2/0x1280 fs/dcache.c:2647
__lookup_slow+0x14f/0x410 fs/namei.c:1682
lookup_slow+0x57/0x70 fs/namei.c:1714
walk_component+0x2f5/0x430 fs/namei.c:2005
lookup_last fs/namei.c:2462 [inline]
path_lookupat+0x155/0x430 fs/namei.c:2486
filename_lookup+0x229/0x580 fs/namei.c:2515
page_owner free stack trace missing
Memory state around the buggy address:
ffff888118088c80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
ffff888118088d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888118088d80: 00 00 fc fc fc fc fc fc fc fc fa fb fb fb fb fb
^
ffff888118088e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888118088e80: fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb
==================================================================
------------[ cut here ]------------
WARNING: CPU: 1 PID: 290 at fs/dcache.c:794 fast_dput+0x207/0x290 fs/dcache.c:794
Modules linked in:
CPU: 1 PID: 290 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:fast_dput+0x207/0x290 fs/dcache.c:794
Code: a4 f1 ff e9 4e fe ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c a1 fe ff ff 48 89 df e8 53 a4 f1 ff e9 94 fe ff ff e8 99 19 ac ff <0f> 0b e9 13 ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c ec fe ff
RSP: 0018:ffffc9000d36faf0 EFLAGS: 00010293
RAX: ffffffff81c53b87 RBX: ffff888118088dd0 RCX: ffff88810d870000
RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001
RBP: ffffc9000d36fb18 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52001a6df50 R12: 00000000ffffff80
R13: dffffc0000000000 R14: ffff888118088e28 R15: 1ffff110230111c5
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4b71bf2b60 CR3: 0000000133355000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
dput+0x21/0x80 fs/dcache.c:905
incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166
incfs_kill_sb+0x1af/0x210 fs/incfs/vfs.c:2003
deactivate_locked_super+0xb5/0x120 fs/super.c:336
deactivate_super+0xaf/0xe0 fs/super.c:367
cleanup_mnt+0x45e/0x4e0 fs/namespace.c:1192
__cleanup_mnt+0x19/0x20 fs/namespace.c:1199
task_work_run+0x1e1/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa7c/0x27c0 kernel/exit.c:886
do_group_exit+0x21b/0x2e0 kernel/exit.c:1029
__do_sys_exit_group kernel/exit.c:1040 [inline]
__se_sys_exit_group kernel/exit.c:1038 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1038
x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f87b019ce59
Code: Unable to access opcode bytes at 0x7f87b019ce2f.
RSP: 002b:00007ffdef8d40f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f87b023222a RCX: 00007f87b019ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f87b02321ca
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdef8d53b0
R13: 00007f87b02321ca R14: 00005555825bb4e8 R15: 00007ffdef8d6480
---[ end trace 0000000000000000 ]---
BUG: unable to handle page fault for address: fffffffffffffffc
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 7012067 P4D 7012067 PUD 7014067 PMD 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 290 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__dentry_kill+0xd0/0x680 fs/dcache.c:599
Code: ff 4d 8b 36 49 83 c6 38 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 bc 8e f1 ff 48 89 df 4d 8b 1e 41 ba ee 71 7a d4 <45> 03 53 fc 74 02 0f 0b 41 ff d3 43 0f b6 04 2c 84 c0 0f 85 bf 04
RSP: 0018:ffffc9000d36fa98 EFLAGS: 00010246
RAX: 1ffffffff0b62fe7 RBX: ffff888118088770 RCX: ffffffff81c55127
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888118088770
RBP: ffffc9000d36fad8 R08: 0000000000000003 R09: 00000000fffffffb
R10: 00000000d47a71ee R11: 0000000000000000 R12: 1ffff110230110ee
R13: dffffc0000000000 R14: ffffffff85b17f38 R15: ffff8881180887c8
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffc CR3: 0000000133355000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
dput+0x42/0x80 fs/dcache.c:918
incfs_free_mount_info+0x80/0x200 fs/incfs/data_mgmt.c:167
incfs_kill_sb+0x1af/0x210 fs/incfs/vfs.c:2003
deactivate_locked_super+0xb5/0x120 fs/super.c:336
deactivate_super+0xaf/0xe0 fs/super.c:367
cleanup_mnt+0x45e/0x4e0 fs/namespace.c:1192
__cleanup_mnt+0x19/0x20 fs/namespace.c:1199
task_work_run+0x1e1/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa7c/0x27c0 kernel/exit.c:886
do_group_exit+0x21b/0x2e0 kernel/exit.c:1029
__do_sys_exit_group kernel/exit.c:1040 [inline]
__se_sys_exit_group kernel/exit.c:1038 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1038
x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f87b019ce59
Code: Unable to access opcode bytes at 0x7f87b019ce2f.
RSP: 002b:00007ffdef8d40f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f87b023222a RCX: 00007f87b019ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f87b02321ca
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdef8d53b0
R13: 00007f87b02321ca R14: 00005555825bb4e8 R15: 00007ffdef8d6480
Modules linked in:
CR2: fffffffffffffffc
---[ end trace 0000000000000000 ]---
RIP: 0010:__dentry_kill+0xd0/0x680 fs/dcache.c:599
Code: ff 4d 8b 36 49 83 c6 38 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 bc 8e f1 ff 48 89 df 4d 8b 1e 41 ba ee 71 7a d4 <45> 03 53 fc 74 02 0f 0b 41 ff d3 43 0f b6 04 2c 84 c0 0f 85 bf 04
RSP: 0018:ffffc9000d36fa98 EFLAGS: 00010246
RAX: 1ffffffff0b62fe7 RBX: ffff888118088770 RCX: ffffffff81c55127
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888118088770
RBP: ffffc9000d36fad8 R08: 0000000000000003 R09: 00000000fffffffb
R10: 00000000d47a71ee R11: 0000000000000000 R12: 1ffff110230110ee
R13: dffffc0000000000 R14: ffffffff85b17f38 R15: ffff8881180887c8
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffc CR3: 0000000133355000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: ff 4d 8b decl -0x75(%rbp)
3: 36 49 83 c6 38 ss add $0x38,%r14
8: 4c 89 f0 mov %r14,%rax
b: 48 c1 e8 03 shr $0x3,%rax
f: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
14: 74 08 je 0x1e
16: 4c 89 f7 mov %r14,%rdi
19: e8 bc 8e f1 ff call 0xfff18eda
1e: 48 89 df mov %rbx,%rdi
21: 4d 8b 1e mov (%r14),%r11
24: 41 ba ee 71 7a d4 mov $0xd47a71ee,%r10d
* 2a: 45 03 53 fc add -0x4(%r11),%r10d <-- trapping instruction
2e: 74 02 je 0x32
30: 0f 0b ud2
32: 41 ff d3 call *%r11
35: 43 0f b6 04 2c movzbl (%r12,%r13,1),%eax
3a: 84 c0 test %al,%al
3c: 0f .byte 0xf
3d: 85 .byte 0x85
3e: bf .byte 0xbf
3f: 04 .byte 0x4