==================================================================
BUG: KASAN: use-after-free in fast_dput+0x1e9/0x290 fs/dcache.c:753
Read of size 4 at addr ffff8881004c8dd0 by task syz-executor/5928
CPU: 0 PID: 5928 Comm: syz-executor Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:88
dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:427 [inline]
kasan_report+0xf1/0x140 mm/kasan/report.c:444
__asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
fast_dput+0x1e9/0x290 fs/dcache.c:753
dput+0x26/0x90 fs/dcache.c:880
incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166
incfs_kill_sb+0x1b8/0x220 fs/incfs/vfs.c:1997
deactivate_locked_super+0xa0/0x100 fs/super.c:335
deactivate_super+0xaf/0xe0 fs/super.c:366
cleanup_mnt+0x446/0x500 fs/namespace.c:1148
__cleanup_mnt+0x19/0x20 fs/namespace.c:1155
task_work_run+0x127/0x190 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0xa7e/0x27a0 kernel/exit.c:889
do_group_exit+0x141/0x310 kernel/exit.c:1003
__do_sys_exit_group kernel/exit.c:1014 [inline]
__se_sys_exit_group kernel/exit.c:1012 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1012
x64_sys_call+0x832/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa2ab126749
Code: Unable to access opcode bytes at RIP 0x7fa2ab12671f.
RSP: 002b:00007ffc0dc2ce68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fa2ab1aaddd RCX: 00007fa2ab126749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 00007ffc0dc2ac07 R09: 00007ffc0dc2e120
R10: 0000000000000009 R11: 0000000000000246 R12: 00007ffc0dc2e120
R13: 00007fa2ab1aad7d R14: 000055557be3d4a8 R15: 00007ffc0dc2f1f0
Allocated by task 9142:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:433 [inline]
__kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:466
kasan_slab_alloc include/linux/kasan.h:217 [inline]
slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550
slab_alloc_node mm/slub.c:3245 [inline]
slab_alloc mm/slub.c:3255 [inline]
kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260
__d_alloc+0x2d/0x6a0 fs/dcache.c:1749
d_alloc fs/dcache.c:1828 [inline]
d_alloc_parallel+0xe1/0x1380 fs/dcache.c:2584
__lookup_slow+0x13e/0x3e0 fs/namei.c:1656
lookup_one_len+0x195/0x2c0 fs/namei.c:2726
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:1884
legacy_get_tree+0xed/0x190 fs/fs_context.c:611
vfs_get_tree+0x89/0x260 fs/super.c:1530
do_new_mount+0x25a/0xa20 fs/namespace.c:3034
path_mount+0x675/0x1020 fs/namespace.c:3364
do_mount fs/namespace.c:3377 [inline]
__do_sys_mount fs/namespace.c:3585 [inline]
__se_sys_mount+0x318/0x380 fs/namespace.c:3562
__x64_sys_mount+0xbf/0xd0 fs/namespace.c:3562
x64_sys_call+0x6bf/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
Freed by task 9178:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365
__kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
kasan_slab_free include/linux/kasan.h:193 [inline]
slab_free_hook mm/slub.c:1728 [inline]
slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754
slab_free mm/slub.c:3526 [inline]
kmem_cache_free+0x100/0x320 mm/slub.c:3544
__d_free+0x23/0x30 fs/dcache.c:273
rcu_do_batch+0x51d/0xba0 kernel/rcu/tree.c:2523
rcu_core+0x5e4/0xf80 kernel/rcu/tree.c:2763
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776
handle_softirqs+0x250/0x560 kernel/softirq.c:583
__do_softirq kernel/softirq.c:621 [inline]
invoke_softirq kernel/softirq.c:443 [inline]
__irq_exit_rcu+0x52/0xf0 kernel/softirq.c:670
irq_exit_rcu+0x9/0x10 kernel/softirq.c:682
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:676
Last potentially related work creation:
kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
__kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
__call_rcu_common kernel/rcu/tree.c:3011 [inline]
call_rcu+0x105/0xfe0 kernel/rcu/tree.c:3129
dentry_free+0xbd/0x150 fs/dcache.c:-1
__dentry_kill+0x50a/0x650 fs/dcache.c:600
dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
dput+0x47/0x90 fs/dcache.c:893
incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166
incfs_kill_sb+0x1b8/0x220 fs/incfs/vfs.c:1997
deactivate_locked_super+0xa0/0x100 fs/super.c:335
deactivate_super+0xaf/0xe0 fs/super.c:366
cleanup_mnt+0x446/0x500 fs/namespace.c:1148
__cleanup_mnt+0x19/0x20 fs/namespace.c:1155
task_work_run+0x127/0x190 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0xa7e/0x27a0 kernel/exit.c:889
do_group_exit+0x141/0x310 kernel/exit.c:1003
__do_sys_exit_group kernel/exit.c:1014 [inline]
__se_sys_exit_group kernel/exit.c:1012 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1012
x64_sys_call+0x832/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
Second to last potentially related work creation:
kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
__kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
__call_rcu_common kernel/rcu/tree.c:3011 [inline]
call_rcu+0x105/0xfe0 kernel/rcu/tree.c:3129
dentry_free+0xbd/0x150 fs/dcache.c:-1
__dentry_kill+0x50a/0x650 fs/dcache.c:600
dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
dput+0x47/0x90 fs/dcache.c:893
do_renameat2+0x8ba/0xf60 fs/namei.c:4995
__do_sys_rename fs/namei.c:5039 [inline]
__se_sys_rename fs/namei.c:5037 [inline]
__x64_sys_rename+0x86/0x90 fs/namei.c:5037
x64_sys_call+0x680/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:83
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
The buggy address belongs to the object at ffff8881004c8dd0
which belongs to the cache dentry of size 208
The buggy address is located 0 bytes inside of
208-byte region [ffff8881004c8dd0, ffff8881004c8ea0)
The buggy address belongs to the page:
page:ffffea0004013200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1004c8
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 dead000000000100 dead000000000122 ffff8881001c4000
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 1, ts 2214374064, free_ts 0
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605
prep_new_page+0x1c/0x110 mm/page_alloc.c:2611
get_page_from_freelist+0x2cc5/0x2d50 mm/page_alloc.c:4485
__alloc_pages+0x18f/0x440 mm/page_alloc.c:5808
alloc_slab_page mm/slub.c:-1 [inline]
allocate_slab mm/slub.c:1937 [inline]
new_slab+0xa1/0x4d0 mm/slub.c:2000
___slab_alloc+0x381/0x810 mm/slub.c:3033
__slab_alloc+0x49/0x90 mm/slub.c:3120
slab_alloc_node mm/slub.c:3211 [inline]
slab_alloc mm/slub.c:3255 [inline]
kmem_cache_alloc+0x138/0x260 mm/slub.c:3260
__d_alloc+0x2d/0x6a0 fs/dcache.c:1749
d_alloc fs/dcache.c:1828 [inline]
d_alloc_name+0xad/0x2e0 fs/dcache.c:1892
simple_fill_super+0x2dc/0x5c0 fs/libfs.c:656
sel_fill_super+0xff/0x1340 security/selinux/selinuxfs.c:2091
vfs_get_super fs/super.c:1172 [inline]
get_tree_single+0xb8/0x170 fs/super.c:1210
sel_get_tree+0x1c/0x20 security/selinux/selinuxfs.c:2187
vfs_get_tree+0x89/0x260 fs/super.c:1530
fc_mount fs/namespace.c:1005 [inline]
vfs_kern_mount+0xcd/0x160 fs/namespace.c:1035
page_owner free stack trace missing
Memory state around the buggy address:
ffff8881004c8c80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
ffff8881004c8d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881004c8d80: 00 00 fc fc fc fc fc fc fc fc fa fb fb fb fb fb
^
ffff8881004c8e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881004c8e80: fb fb fb fb fc fc fc fc fc fc fc fc 00 00 00 00
==================================================================
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5928 at fs/dcache.c:769 fast_dput+0x210/0x290 fs/dcache.c:769
Modules linked in:
CPU: 1 PID: 5928 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:fast_dput+0x210/0x290 fs/dcache.c:769
Code: 15 f3 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 ba 15 f3 ff e9 8c fe ff ff e8 20 93 b4 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:ffffc90000a3fb40 EFLAGS: 00010293
RAX: ffffffff81b42c30 RBX: ffff8881004c8dd0 RCX: ffff88812bb713c0
RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001
RBP: ffffc90000a3fb70 R08: 0000000000000004 R09: 0000000000000003
R10: fffff52000147f58 R11: 1ffff92000147f58 R12: 00000000ffffff80
R13: dffffc0000000000 R14: ffff8881004c8e28 R15: 1ffff110200991c5
FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff80cbd0000 CR3: 0000000147b8c000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
dput+0x26/0x90 fs/dcache.c:880
incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166
incfs_kill_sb+0x1b8/0x220 fs/incfs/vfs.c:1997
deactivate_locked_super+0xa0/0x100 fs/super.c:335
deactivate_super+0xaf/0xe0 fs/super.c:366
cleanup_mnt+0x446/0x500 fs/namespace.c:1148
__cleanup_mnt+0x19/0x20 fs/namespace.c:1155
task_work_run+0x127/0x190 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0xa7e/0x27a0 kernel/exit.c:889
do_group_exit+0x141/0x310 kernel/exit.c:1003
__do_sys_exit_group kernel/exit.c:1014 [inline]
__se_sys_exit_group kernel/exit.c:1012 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1012
x64_sys_call+0x832/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa2ab126749
Code: Unable to access opcode bytes at RIP 0x7fa2ab12671f.
RSP: 002b:00007ffc0dc2ce68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fa2ab1aaddd RCX: 00007fa2ab126749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 00007ffc0dc2ac07 R09: 00007ffc0dc2e120
R10: 0000000000000009 R11: 0000000000000246 R12: 00007ffc0dc2e120
R13: 00007fa2ab1aad7d R14: 000055557be3d4a8 R15: 00007ffc0dc2f1f0
---[ end trace 453932fac5b9d799 ]---
list_del corruption. prev->next should be ffff88812ac861a0, but was ffff88812fdd71a0
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:61!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 5928 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__list_del_entry_valid+0x10c/0x120 lib/list_debug.c:59
Code: 48 89 de e8 56 d9 4f 02 0f 0b 48 c7 c7 80 4d 63 85 48 89 de e8 45 d9 4f 02 0f 0b 48 c7 c7 e0 4d 63 85 48 89 de e8 34 d9 4f 02 <0f> 0b 48 c7 c7 40 4e 63 85 48 89 de e8 23 d9 4f 02 0f 0b 00 55 48
RSP: 0018:ffffc90000a3fab8 EFLAGS: 00010246
RAX: 0000000000000054 RBX: ffff88812ac861a0 RCX: 09de4b5092f3d500
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc90000a3fad8 R08: 0000000000000004 R09: 0000000000000003
R10: fffff52000147eb8 R11: 1ffff92000147eb8 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88812fdd71a0 R15: ffff888111d59f70
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ded7956338 CR3: 000000015d53b000 CR4: 00000000003506b0
Call Trace:
__list_del_entry include/linux/list.h:132 [inline]
dentry_unlist fs/dcache.c:529 [inline]
__dentry_kill+0x24c/0x650 fs/dcache.c:582
dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
dput+0x47/0x90 fs/dcache.c:893
incfs_free_mount_info+0x80/0x200 fs/incfs/data_mgmt.c:167
incfs_kill_sb+0x1b8/0x220 fs/incfs/vfs.c:1997
deactivate_locked_super+0xa0/0x100 fs/super.c:335
deactivate_super+0xaf/0xe0 fs/super.c:366
cleanup_mnt+0x446/0x500 fs/namespace.c:1148
__cleanup_mnt+0x19/0x20 fs/namespace.c:1155
task_work_run+0x127/0x190 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0xa7e/0x27a0 kernel/exit.c:889
do_group_exit+0x141/0x310 kernel/exit.c:1003
__do_sys_exit_group kernel/exit.c:1014 [inline]
__se_sys_exit_group kernel/exit.c:1012 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1012
x64_sys_call+0x832/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa2ab126749
Code: Unable to access opcode bytes at RIP 0x7fa2ab12671f.
RSP: 002b:00007ffc0dc2ce68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fa2ab1aaddd RCX: 00007fa2ab126749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 00007ffc0dc2ac07 R09: 00007ffc0dc2e120
R10: 0000000000000009 R11: 0000000000000246 R12: 00007ffc0dc2e120
R13: 00007fa2ab1aad7d R14: 000055557be3d4a8 R15: 00007ffc0dc2f1f0
Modules linked in:
---[ end trace 453932fac5b9d79a ]---
RIP: 0010:__list_del_entry_valid+0x10c/0x120 lib/list_debug.c:59
Code: 48 89 de e8 56 d9 4f 02 0f 0b 48 c7 c7 80 4d 63 85 48 89 de e8 45 d9 4f 02 0f 0b 48 c7 c7 e0 4d 63 85 48 89 de e8 34 d9 4f 02 <0f> 0b 48 c7 c7 40 4e 63 85 48 89 de e8 23 d9 4f 02 0f 0b 00 55 48
RSP: 0018:ffffc90000a3fab8 EFLAGS: 00010246
RAX: 0000000000000054 RBX: ffff88812ac861a0 RCX: 09de4b5092f3d500
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc90000a3fad8 R08: 0000000000000004 R09: 0000000000000003
R10: fffff52000147eb8 R11: 1ffff92000147eb8 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88812fdd71a0 R15: ffff888111d59f70
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ded7956338 CR3: 000000000660f000 CR4: 00000000003506b0