==================================================================
BUG: KASAN: use-after-free in fast_dput+0x1e9/0x290 fs/dcache.c:778
Read of size 4 at addr ffff888116decdd0 by task syz-executor/2354
CPU: 1 PID: 2354 Comm: syz-executor Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
__dump_stack+0x21/0x24 lib/dump_stack.c:88
dump_stack_lvl+0xee/0x150 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+0x1e9/0x290 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+0x1b8/0x220 fs/incfs/vfs.c:2003
deactivate_locked_super+0xb5/0x120 fs/super.c:334
deactivate_super+0xaf/0xe0 fs/super.c:365
cleanup_mnt+0x45f/0x4e0 fs/namespace.c:1182
__cleanup_mnt+0x19/0x20 fs/namespace.c:1189
task_work_run+0x1db/0x240 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa25/0x2650 kernel/exit.c:886
do_group_exit+0x210/0x2d0 kernel/exit.c:1028
__do_sys_exit_group kernel/exit.c:1039 [inline]
__se_sys_exit_group kernel/exit.c:1037 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1037
x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4e0ed8efc9
Code: Unable to access opcode bytes at 0x7f4e0ed8ef9f.
RSP: 002b:00007fffc2276798 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f4e0ee11ddd RCX: 00007f4e0ed8efc9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 00007fffc2274537 R09: 00007fffc2277a50
R10: 0000000000000009 R11: 0000000000000246 R12: 00007fffc2277a50
R13: 00007f4e0ee11d7d R14: 0000555561fc04a8 R15: 00007fffc2278b20
Allocated by task 3592:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505
__kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:333
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+0x34/0x6c0 fs/dcache.c:1774
d_alloc fs/dcache.c:1854 [inline]
d_alloc_parallel+0xd6/0x1240 fs/dcache.c:2645
__lookup_slow+0x141/0x3f0 fs/namei.c:1674
lookup_one_len+0x195/0x2d0 fs/namei.c:2739
incfs_lookup_dentry+0x60/0xb0 fs/incfs/data_mgmt.c:210
open_or_create_special_dir+0x4f/0x1d0 fs/incfs/vfs.c:475
incfs_mount_fs+0x42f/0x880 fs/incfs/vfs.c:1890
legacy_get_tree+0xfe/0x1a0 fs/fs_context.c:632
vfs_get_tree+0x9a/0x270 fs/super.c:1575
do_new_mount+0x25a/0xa20 fs/namespace.c:3069
path_mount+0x675/0x1010 fs/namespace.c:3399
do_mount fs/namespace.c:3412 [inline]
__do_sys_mount fs/namespace.c:3620 [inline]
__se_sys_mount+0x318/0x380 fs/namespace.c:3597
__x64_sys_mount+0xbf/0xd0 fs/namespace.c:3597
x64_sys_call+0x65d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Freed by task 23:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516
____kasan_slab_free+0x132/0x180 mm/kasan/common.c:241
__kasan_slab_free+0x11/0x20 mm/kasan/common.c:249
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+0x515/0xb90 kernel/rcu/tree.c:2297
rcu_core+0x5a5/0xe70 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+0x4a0/0x910 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:45
__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+0xd4/0xf90 kernel/rcu/tree.c:2926
dentry_free+0xbd/0x150 fs/dcache.c:-1
__dentry_kill+0x529/0x670 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+0x1b8/0x220 fs/incfs/vfs.c:2003
deactivate_locked_super+0xb5/0x120 fs/super.c:334
deactivate_super+0xaf/0xe0 fs/super.c:365
cleanup_mnt+0x45f/0x4e0 fs/namespace.c:1182
__cleanup_mnt+0x19/0x20 fs/namespace.c:1189
task_work_run+0x1db/0x240 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa25/0x2650 kernel/exit.c:886
do_group_exit+0x210/0x2d0 kernel/exit.c:1028
__do_sys_exit_group kernel/exit.c:1039 [inline]
__se_sys_exit_group kernel/exit.c:1037 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1037
x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Second to last potentially related work creation:
kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45
__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+0xd4/0xf90 kernel/rcu/tree.c:2926
dentry_free+0xbd/0x150 fs/dcache.c:-1
__dentry_kill+0x529/0x670 fs/dcache.c:625
dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
dput+0x42/0x80 fs/dcache.c:918
dcache_dir_close+0x3b/0x40 fs/libfs.c:91
__fput+0x1fc/0x8f0 fs/file_table.c:320
____fput+0x15/0x20 fs/file_table.c:348
task_work_run+0x1db/0x240 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177
exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
The buggy address belongs to the object at ffff888116decdd0
which belongs to the cache dentry of size 208
The buggy address is located 0 bytes inside of
208-byte region [ffff888116decdd0, ffff888116decea0)
The buggy address belongs to the physical page:
page:ffffea00045b7b00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x116dec
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 ffffea00045b1cc0 dead000000000002 ffff8881001ec780
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 285, tgid 285 (syz-executor), ts 23215440726, free_ts 0
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643
prep_new_page+0x1c/0x110 mm/page_alloc.c:2650
get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4554
__alloc_pages+0x1c3/0x450 mm/page_alloc.c:5868
alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
allocate_slab mm/slub.c:1967 [inline]
new_slab+0x98/0x3d0 mm/slub.c:2020
___slab_alloc+0x6bd/0xb20 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+0x34/0x6c0 fs/dcache.c:1774
d_alloc_pseudo+0x1d/0x70 fs/dcache.c:1904
alloc_file_pseudo+0xc8/0x1f0 fs/file_table.c:265
sock_alloc_file+0xba/0x270 net/socket.c:465
sock_map_fd net/socket.c:489 [inline]
__sys_socket+0x135/0x1a0 net/socket.c:1669
__do_sys_socket net/socket.c:1674 [inline]
__se_sys_socket net/socket.c:1672 [inline]
__x64_sys_socket+0x7a/0x90 net/socket.c:1672
x64_sys_call+0x449/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:42
page_owner free stack trace missing
Memory state around the buggy address:
ffff888116decc80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
ffff888116decd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888116decd80: fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb fb
^
ffff888116dece00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888116dece80: fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb
==================================================================
------------[ cut here ]------------
WARNING: CPU: 0 PID: 2354 at fs/dcache.c:794 fast_dput+0x210/0x290 fs/dcache.c:794
Modules linked in:
CPU: 0 PID: 2354 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:fast_dput+0x210/0x290 fs/dcache.c:794
Code: d2 f1 ff e9 46 fe ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 99 fe ff ff 48 89 df e8 1a d2 f1 ff e9 8c fe ff ff e8 f0 62 ad ff <0f> 0b e9 0b ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c e4 fe ff
RSP: 0018:ffffc9000424fad0 EFLAGS: 00010293
RAX: ffffffff81c2bb30 RBX: ffff888116decdd0 RCX: ffff88811f100000
RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001
RBP: ffffc9000424fb00 R08: 0000000000000004 R09: 0000000000000003
R10: fffff52000849f4c R11: 1ffff92000849f4c R12: 00000000ffffff80
R13: dffffc0000000000 R14: ffff888116dece28 R15: 1ffff11022dbd9c5
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34b22ff8 CR3: 0000000136026000 CR4: 00000000003506b0
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+0x1b8/0x220 fs/incfs/vfs.c:2003
deactivate_locked_super+0xb5/0x120 fs/super.c:334
deactivate_super+0xaf/0xe0 fs/super.c:365
cleanup_mnt+0x45f/0x4e0 fs/namespace.c:1182
__cleanup_mnt+0x19/0x20 fs/namespace.c:1189
task_work_run+0x1db/0x240 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa25/0x2650 kernel/exit.c:886
do_group_exit+0x210/0x2d0 kernel/exit.c:1028
__do_sys_exit_group kernel/exit.c:1039 [inline]
__se_sys_exit_group kernel/exit.c:1037 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1037
x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4e0ed8efc9
Code: Unable to access opcode bytes at 0x7f4e0ed8ef9f.
RSP: 002b:00007fffc2276798 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f4e0ee11ddd RCX: 00007f4e0ed8efc9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 00007fffc2274537 R09: 00007fffc2277a50
R10: 0000000000000009 R11: 0000000000000246 R12: 00007fffc2277a50
R13: 00007f4e0ee11d7d R14: 0000555561fc04a8 R15: 00007fffc2278b20
---[ end trace 0000000000000000 ]---
list_del corruption. prev->next should be ffff888116dec800, but was ffff888116dec2b0. (prev=ffff888116d864e0)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:61!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 2354 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__list_del_entry_valid+0x10f/0x130 lib/list_debug.c:59
Code: e8 2e c9 80 02 0f 0b 48 c7 c7 a0 15 aa 85 48 89 de e8 1d c9 80 02 0f 0b 48 c7 c7 00 16 aa 85 48 89 de 4c 89 f9 e8 09 c9 80 02 <0f> 0b 48 c7 c7 80 16 aa 85 48 89 de 4c 89 f1 e8 f5 c8 80 02 0f 0b
RSP: 0018:ffffc9000424fa48 EFLAGS: 00010246
RAX: 000000000000006d RBX: ffff888116dec800 RCX: 20874d919f749700
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc9000424fa68 R08: dffffc0000000000 R09: fffff52000849ec5
R10: fffff52000849ec5 R11: 1ffff92000849ec4 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888116dec2b0 R15: ffff888116d864e0
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff711bb4198 CR3: 0000000136026000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__list_del_entry include/linux/list.h:134 [inline]
dentry_unlist fs/dcache.c:554 [inline]
__dentry_kill+0x25d/0x670 fs/dcache.c:607
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+0x1b8/0x220 fs/incfs/vfs.c:2003
deactivate_locked_super+0xb5/0x120 fs/super.c:334
deactivate_super+0xaf/0xe0 fs/super.c:365
cleanup_mnt+0x45f/0x4e0 fs/namespace.c:1182
__cleanup_mnt+0x19/0x20 fs/namespace.c:1189
task_work_run+0x1db/0x240 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa25/0x2650 kernel/exit.c:886
do_group_exit+0x210/0x2d0 kernel/exit.c:1028
__do_sys_exit_group kernel/exit.c:1039 [inline]
__se_sys_exit_group kernel/exit.c:1037 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1037
x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4e0ed8efc9
Code: Unable to access opcode bytes at 0x7f4e0ed8ef9f.
RSP: 002b:00007fffc2276798 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f4e0ee11ddd RCX: 00007f4e0ed8efc9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 00007fffc2274537 R09: 00007fffc2277a50
R10: 0000000000000009 R11: 0000000000000246 R12: 00007fffc2277a50
R13: 00007f4e0ee11d7d R14: 0000555561fc04a8 R15: 00007fffc2278b20
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid+0x10f/0x130 lib/list_debug.c:59
Code: e8 2e c9 80 02 0f 0b 48 c7 c7 a0 15 aa 85 48 89 de e8 1d c9 80 02 0f 0b 48 c7 c7 00 16 aa 85 48 89 de 4c 89 f9 e8 09 c9 80 02 <0f> 0b 48 c7 c7 80 16 aa 85 48 89 de 4c 89 f1 e8 f5 c8 80 02 0f 0b
RSP: 0018:ffffc9000424fa48 EFLAGS: 00010246
RAX: 000000000000006d RBX: ffff888116dec800 RCX: 20874d919f749700
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc9000424fa68 R08: dffffc0000000000 R09: fffff52000849ec5
R10: fffff52000849ec5 R11: 1ffff92000849ec4 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888116dec2b0 R15: ffff888116d864e0
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff711bb4198 CR3: 0000000136026000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400