R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffeb9fa510
R13: 00007f8376a31f90 R14: 000055557add44e8 R15: 00007fffeb9fb5e0
---[ end trace 0000000000000000 ]---
==================================================================
BUG: KASAN: use-after-free in fast_dput+0x1e9/0x290 fs/dcache.c:778
Read of size 4 at addr ffff888116c08220 by task syz-executor/2787
CPU: 0 PID: 2787 Comm: syz-executor Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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+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+0x474/0x500 fs/namespace.c:1191
__cleanup_mnt+0x19/0x20 fs/namespace.c:1198
task_work_run+0x1e1/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa35/0x2660 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:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f837699c799
Code: Unable to access opcode bytes at 0x7f837699c76f.
RSP: 002b:00007fffeb9f9258 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f8376a31ff0 RCX: 00007f837699c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f8376a31f90
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffeb9fa510
R13: 00007f8376a31f90 R14: 000055557add44e8 R15: 00007fffeb9fb5e0
Allocated by task 3063:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_alloc_info+0x25/0x30 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+0x34/0x6c0 fs/dcache.c:1774
d_alloc fs/dcache.c:1854 [inline]
d_alloc_parallel+0xe2/0x12e0 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+0x4f/0x1d0 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:1575
do_new_mount+0x25a/0xa20 fs/namespace.c:3078
path_mount+0x659/0xfc0 fs/namespace.c:3408
do_mount fs/namespace.c:3421 [inline]
__do_sys_mount fs/namespace.c:3629 [inline]
__se_sys_mount+0x320/0x390 fs/namespace.c:3606
__x64_sys_mount+0xbf/0xd0 fs/namespace.c:3606
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+0x31/0x50 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+0x52a/0xbc0 kernel/rcu/tree.c:2297
rcu_core+0x5c3/0xe80 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: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/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+0x474/0x500 fs/namespace.c:1191
__cleanup_mnt+0x19/0x20 fs/namespace.c:1198
task_work_run+0x1e1/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa35/0x2660 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: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/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+0x1e1/0x250 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+0x87/0xd0 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:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
The buggy address belongs to the object at ffff888116c08220
which belongs to the cache dentry of size 208
The buggy address is located 0 bytes inside of
208-byte region [ffff888116c08220, ffff888116c082f0)
The buggy address belongs to the physical page:
page:ffffea00045b0200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x116c08
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 dead000000000001 ffff8881001ecc00
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 108, tgid 108 (udevd), ts 7251411592, free_ts 0
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2670
prep_new_page+0x1c/0x110 mm/page_alloc.c:2677
get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4583
__alloc_pages+0x1d9/0x480 mm/page_alloc.c:5897
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 fs/dcache.c:1854 [inline]
d_alloc_parallel+0xe2/0x12e0 fs/dcache.c:2647
lookup_open fs/namei.c:3414 [inline]
open_last_lookups fs/namei.c:3557 [inline]
path_openat+0x961/0x2f80 fs/namei.c:3787
do_filp_open+0x1f1/0x430 fs/namei.c:3817
do_sys_openat2+0x15e/0x810 fs/open.c:1343
do_sys_open fs/open.c:1359 [inline]
__do_sys_openat fs/open.c:1375 [inline]
__se_sys_openat fs/open.c:1370 [inline]
__x64_sys_openat+0x136/0x160 fs/open.c:1370
x64_sys_call+0x783/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258
page_owner free stack trace missing
Memory state around the buggy address:
ffff888116c08100: fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888116c08180: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff888116c08200: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb
^
ffff888116c08280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
ffff888116c08300: fc fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00
==================================================================
------------[ cut here ]------------
WARNING: CPU: 1 PID: 2787 at fs/dcache.c:794 fast_dput+0x210/0x290 fs/dcache.c:794
Modules linked in:
CPU: 1 PID: 2787 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:fast_dput+0x210/0x290 fs/dcache.c:794
Code: a0 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 7a a0 f1 ff e9 8c fe ff ff e8 20 6e ac 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:ffffc9000869fad0 EFLAGS: 00010293
RAX: ffffffff81c4fee0 RBX: ffff888116c08220 RCX: ffff88813d930000
RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001
RBP: ffffc9000869fb00 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520010d3f4c R12: 00000000ffffff80
R13: dffffc0000000000 R14: ffff888116c08278 R15: 1ffff11022d8104f
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0cacde6eb8 CR3: 00000001273d6000 CR4: 00000000003506a0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 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+0x474/0x500 fs/namespace.c:1191
__cleanup_mnt+0x19/0x20 fs/namespace.c:1198
task_work_run+0x1e1/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa35/0x2660 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:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f837699c799
Code: Unable to access opcode bytes at 0x7f837699c76f.
RSP: 002b:00007fffeb9f9258 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f8376a31ff0 RCX: 00007f837699c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f8376a31f90
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffeb9fa510
R13: 00007f8376a31f90 R14: 000055557add44e8 R15: 00007fffeb9fb5e0
---[ end trace 0000000000000000 ]---