R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc7c08f720
R13: 00007f661a8da048 R14: 000055557647f4e8 R15: 00007ffc7c0907f0
---[ end trace f7ea402bd266329e ]---
==================================================================
BUG: KASAN: use-after-free in fast_dput+0x1e9/0x290 fs/dcache.c:753
Read of size 4 at addr ffff888129750cc0 by task syz-executor/5226
CPU: 1 PID: 5226 Comm: syz-executor Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:88
dump_stack_lvl+0x110/0x170 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+0x45b/0x510 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+0xa9e/0x27e0 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: 0033:0x7f661a844819
Code: Unable to access opcode bytes at RIP 0x7f661a8447ef.
RSP: 002b:00007ffc7c08e468 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f661a8da0a8 RCX: 00007f661a844819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f661a8da048
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc7c08f720
R13: 00007f661a8da048 R14: 000055557647f4e8 R15: 00007ffc7c0907f0
Allocated by task 5880:
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+0xe2/0x1370 fs/dcache.c:2584
__lookup_slow+0x14c/0x410 fs/namei.c:1656
lookup_one_len+0x19d/0x2d0 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/0x890 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+0x659/0xff0 fs/namespace.c:3364
do_mount fs/namespace.c:3377 [inline]
__do_sys_mount fs/namespace.c:3585 [inline]
__se_sys_mount+0x320/0x390 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 0:
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+0x532/0xbe0 kernel/rcu/tree.c:2523
rcu_core+0x5ee/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+0x10b/0xf80 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+0x45b/0x510 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+0xa9e/0x27e0 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+0x10b/0xf80 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
handle_mounts fs/namei.c:1514 [inline]
step_into+0x92a/0xd20 fs/namei.c:1814
walk_component+0x26a/0x460 fs/namei.c:1990
lookup_last fs/namei.c:2439 [inline]
path_lookupat+0x180/0x490 fs/namei.c:2463
filename_lookup+0x214/0x540 fs/namei.c:2492
user_path_at_empty+0x47/0x1c0 fs/namei.c:2891
user_path_at include/linux/namei.h:57 [inline]
vfs_statx+0x109/0xa20 fs/stat.c:221
vfs_fstatat fs/stat.c:243 [inline]
__do_sys_newfstatat fs/stat.c:411 [inline]
__se_sys_newfstatat+0x10e/0x3d0 fs/stat.c:405
__x64_sys_newfstatat+0x9b/0xb0 fs/stat.c:405
x64_sys_call+0x2c1/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:263
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 ffff888129750cc0
which belongs to the cache dentry of size 208
The buggy address is located 0 bytes inside of
208-byte region [ffff888129750cc0, ffff888129750d90)
The buggy address belongs to the page:
page:ffffea0004a5d400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x129750
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 ffffea0004c27bc0 0000000300000003 ffff8881001c4780
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 0x112cd0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_RECLAIMABLE), pid 28, ts 39376021952, 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+0x2d3a/0x2dc0 mm/page_alloc.c:4485
__alloc_pages+0x1a2/0x460 mm/page_alloc.c:5822
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+0x4b/0x260 fs/dcache.c:1828
lookup_one_qstr_excl+0xcb/0x250 fs/namei.c:1567
filename_create+0x235/0x470 fs/namei.c:3844
kern_path_create+0x39/0x1b0 fs/namei.c:3884
handle_create drivers/base/devtmpfs.c:214 [inline]
handle drivers/base/devtmpfs.c:387 [inline]
devtmpfs_work_loop+0x22b/0xe20 drivers/base/devtmpfs.c:402
devtmpfsd+0x49/0x50 drivers/base/devtmpfs.c:444
kthread+0x411/0x500 kernel/kthread.c:337
page_owner free stack trace missing
Memory state around the buggy address:
ffff888129750b80: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb
ffff888129750c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888129750c80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
^
ffff888129750d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888129750d80: fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb fb
==================================================================
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5226 at fs/dcache.c:769 fast_dput+0x210/0x290 fs/dcache.c:769
Modules linked in:
CPU: 0 PID: 5226 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:fast_dput+0x210/0x290 fs/dcache.c:769
Code: e5 f2 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 ea e4 f2 ff e9 8c fe ff ff e8 50 b6 b3 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:ffffc90000b67b40 EFLAGS: 00010293
RAX: ffffffff81b61090 RBX: ffff888129750cc0 RCX: ffff8881118ebb40
RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001
RBP: ffffc90000b67b70 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200016cf58 R12: 00000000ffffff80
R13: dffffc0000000000 R14: ffff888129750d18 R15: 1ffff110252ea1a3
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f61565a02f8 CR3: 000000010d416000 CR4: 00000000003506b0
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+0x45b/0x510 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+0xa9e/0x27e0 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: 0033:0x7f661a844819
Code: Unable to access opcode bytes at RIP 0x7f661a8447ef.
RSP: 002b:00007ffc7c08e468 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f661a8da0a8 RCX: 00007f661a844819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f661a8da048
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc7c08f720
R13: 00007f661a8da048 R14: 000055557647f4e8 R15: 00007ffc7c0907f0
---[ end trace f7ea402bd266329f ]---
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 1103ef067 P4D 1103ef067 PUD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 5226 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90000b67ae0 EFLAGS: 00010246
RAX: 1ffffffff0a97d2f RBX: ffff888129750990 RCX: ffffffff81b624c7
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888129750990
RBP: ffffc90000b67b30 R08: 0000000000000003 R09: fffffffffffffffb
R10: dffffc0000000000 R11: ffffed10252ea13d R12: 1ffff110252ea132
R13: dffffc0000000000 R14: ffffffff854be978 R15: ffff8881297509e8
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000123d17000 CR4: 00000000003506b0
Call Trace:
__dentry_kill+0xca/0x650 fs/dcache.c:574
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+0x45b/0x510 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+0xa9e/0x27e0 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: 0033:0x7f661a844819
Code: Unable to access opcode bytes at RIP 0x7f661a8447ef.
RSP: 002b:00007ffc7c08e468 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f661a8da0a8 RCX: 00007f661a844819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f661a8da048
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc7c08f720
R13: 00007f661a8da048 R14: 000055557647f4e8 R15: 00007ffc7c0907f0
Modules linked in:
CR2: 0000000000000000
---[ end trace f7ea402bd26632a0 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90000b67ae0 EFLAGS: 00010246
RAX: 1ffffffff0a97d2f RBX: ffff888129750990 RCX: ffffffff81b624c7
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888129750990
RBP: ffffc90000b67b30 R08: 0000000000000003 R09: fffffffffffffffb
R10: dffffc0000000000 R11: ffffed10252ea13d R12: 1ffff110252ea132
R13: dffffc0000000000 R14: ffffffff854be978 R15: ffff8881297509e8
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000123d17000 CR4: 00000000003506b0