R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff42a48ed0
R13: 00007fb01d7b030a R14: 000055558d3844e8 R15: 00007fff42a49fa0
---[ end trace 5cca9f346d556a15 ]---
==================================================================
BUG: KASAN: use-after-free in fast_dput+0x1e0/0x290 fs/dcache.c:753
Read of size 4 at addr ffff888111d82220 by task syz-executor/3100
CPU: 1 PID: 3100 Comm: syz-executor Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
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+0x10f/0x150 mm/kasan/report.c:444
__asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
fast_dput+0x1e0/0x290 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+0x1af/0x210 fs/incfs/vfs.c:1997
deactivate_locked_super+0xa0/0x100 fs/super.c:335
deactivate_super+0xaf/0xe0 fs/super.c:366
cleanup_mnt+0x44f/0x500 fs/namespace.c:1149
__cleanup_mnt+0x19/0x20 fs/namespace.c:1156
task_work_run+0x127/0x190 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0xb70/0x29a0 kernel/exit.c:890
do_group_exit+0x149/0x310 kernel/exit.c:1004
__do_sys_exit_group kernel/exit.c:1015 [inline]
__se_sys_exit_group kernel/exit.c:1013 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1013
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: 0033:0x7fb01d71ae99
Code: Unable to access opcode bytes at RIP 0x7fb01d71ae6f.
RSP: 002b:00007fff42a47c18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fb01d7b036a RCX: 00007fb01d71ae99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007fb01d7b030a
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff42a48ed0
R13: 00007fb01d7b030a R14: 000055558d3844e8 R15: 00007fff42a49fa0
Allocated by task 3914:
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+0xb7/0xe0 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/0x690 fs/dcache.c:1749
d_alloc fs/dcache.c:1828 [inline]
d_alloc_parallel+0xe5/0x1380 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+0x4c/0x1f0 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+0x251/0xb40 fs/namespace.c:3037
path_mount+0x640/0xff0 fs/namespace.c:3367
do_mount fs/namespace.c:3380 [inline]
__do_sys_mount fs/namespace.c:3588 [inline]
__se_sys_mount+0x320/0x390 fs/namespace.c:3565
__x64_sys_mount+0xbf/0xd0 fs/namespace.c:3565
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+0x4c1/0xbf0 kernel/rcu/tree.c:2523
rcu_core+0x4a3/0xef0 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_call_function_single arch/x86/kernel/smp.c:243 [inline]
sysvec_call_function_single+0xa6/0xc0 arch/x86/kernel/smp.c:243
asm_sysvec_call_function_single+0x1b/0x20 arch/x86/include/asm/idtentry.h:684
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/0xf60 kernel/rcu/tree.c:3129
dentry_free+0xbd/0x150 fs/dcache.c:-1
__dentry_kill+0x516/0x660 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+0x1af/0x210 fs/incfs/vfs.c:1997
deactivate_locked_super+0xa0/0x100 fs/super.c:335
deactivate_super+0xaf/0xe0 fs/super.c:366
cleanup_mnt+0x44f/0x500 fs/namespace.c:1149
__cleanup_mnt+0x19/0x20 fs/namespace.c:1156
task_work_run+0x127/0x190 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0xb70/0x29a0 kernel/exit.c:890
do_group_exit+0x149/0x310 kernel/exit.c:1004
__do_sys_exit_group kernel/exit.c:1015 [inline]
__se_sys_exit_group kernel/exit.c:1013 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1013
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/0xf60 kernel/rcu/tree.c:3129
dentry_free+0xbd/0x150 fs/dcache.c:-1
__dentry_kill+0x516/0x660 fs/dcache.c:600
shrink_dentry_list+0x38e/0x500 fs/dcache.c:1181
shrink_dcache_parent+0xa9/0x270 fs/dcache.c:-1
d_invalidate+0x112/0x260 fs/dcache.c:1717
proc_invalidate_siblings_dcache+0x298/0x3c0 fs/proc/inode.c:150
proc_flush_pid+0x1d/0x20 fs/proc/base.c:3436
release_task+0x10c9/0x1210 kernel/exit.c:271
wait_task_zombie kernel/exit.c:1189 [inline]
wait_consider_task+0x1829/0x2840 kernel/exit.c:1416
do_wait_thread kernel/exit.c:1479 [inline]
do_wait+0x267/0x9c0 kernel/exit.c:1596
kernel_wait4+0x1d1/0x2b0 kernel/exit.c:1759
__do_sys_wait4 kernel/exit.c:1787 [inline]
__se_sys_wait4 kernel/exit.c:1783 [inline]
__x64_sys_wait4+0x163/0x230 kernel/exit.c:1783
x64_sys_call+0xec/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:62
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 ffff888111d82220
which belongs to the cache dentry of size 208
The buggy address is located 0 bytes inside of
208-byte region [ffff888111d82220, ffff888111d822f0)
The buggy address belongs to the page:
page:ffffea0004476080 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111d82
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 0000000700000001 ffff8881001c4900
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 378, ts 102744128072, free_ts 92363474777
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607
prep_new_page+0x1c/0x110 mm/page_alloc.c:2613
get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487
__alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824
alloc_slab_page mm/slub.c:-1 [inline]
allocate_slab mm/slub.c:1937 [inline]
new_slab+0xa0/0x4d0 mm/slub.c:2000
___slab_alloc+0x3ac/0x840 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/0x690 fs/dcache.c:1749
d_alloc_anon fs/dcache.c:1849 [inline]
d_alloc_cursor+0x41/0xd0 fs/dcache.c:1855
dcache_dir_open+0x3b/0x80 fs/libfs.c:82
do_dentry_open+0x82a/0x1010 fs/open.c:828
vfs_open+0x73/0x80 fs/open.c:960
do_open fs/namei.c:3616 [inline]
path_openat+0x26e6/0x2f80 fs/namei.c:3750
do_filp_open+0x1df/0x400 fs/namei.c:3777
do_sys_openat2+0x15e/0x7f0 fs/open.c:1236
page last free stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
free_pages_prepare mm/page_alloc.c:1474 [inline]
free_pcp_prepare mm/page_alloc.c:1546 [inline]
free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3536
free_unref_page+0xae/0x540 mm/page_alloc.c:3618
free_the_page mm/page_alloc.c:805 [inline]
__free_pages+0x6c/0x100 mm/page_alloc.c:5900
__free_slab+0xe5/0x1e0 mm/slub.c:2025
free_slab mm/slub.c:2040 [inline]
discard_slab+0x29/0x40 mm/slub.c:2046
__slab_free+0x211/0x290 mm/slub.c:3431
do_slab_free mm/slub.c:3514 [inline]
___cache_free+0x104/0x120 mm/slub.c:3535
qlink_free+0x4d/0x90 mm/kasan/quarantine.c:157
qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176
kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:283
____kasan_kmalloc mm/kasan/common.c:478 [inline]
__kasan_kmalloc+0x2f/0x100 mm/kasan/common.c:521
kasan_kmalloc include/linux/kasan.h:227 [inline]
__kmalloc_track_caller+0x13c/0x2c0 mm/slub.c:4959
kmalloc_reserve net/core/skbuff.c:357 [inline]
__alloc_skb+0x210/0x730 net/core/skbuff.c:428
alloc_skb include/linux/skbuff.h:1183 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1186 [inline]
netlink_sendmsg+0x611/0xb80 net/netlink/af_netlink.c:1902
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
__sys_sendto+0x46d/0x620 net/socket.c:2063
__do_sys_sendto net/socket.c:2075 [inline]
__se_sys_sendto net/socket.c:2071 [inline]
__x64_sys_sendto+0xe5/0x100 net/socket.c:2071
Memory state around the buggy address:
ffff888111d82100: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888111d82180: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff888111d82200: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb
^
ffff888111d82280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
ffff888111d82300: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
WARNING: CPU: 0 PID: 3100 at fs/dcache.c:769 fast_dput+0x207/0x290 fs/dcache.c:769
Modules linked in:
CPU: 0 PID: 3100 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:fast_dput+0x207/0x290 fs/dcache.c:769
Code: ed f2 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 e3 ec f2 ff e9 94 fe ff ff e8 49 7b b3 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:ffffc90001f47b60 EFLAGS: 00010293
RAX: ffffffff81b63b57 RBX: ffff888111d82220 RCX: ffff888119d8a780
RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001
RBP: ffffc90001f47b88 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520003e8f5c R12: 00000000ffffff80
R13: dffffc0000000000 R14: ffff888111d82278 R15: 1ffff110223b044f
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000000660f000 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+0x1af/0x210 fs/incfs/vfs.c:1997
deactivate_locked_super+0xa0/0x100 fs/super.c:335
deactivate_super+0xaf/0xe0 fs/super.c:366
cleanup_mnt+0x44f/0x500 fs/namespace.c:1149
__cleanup_mnt+0x19/0x20 fs/namespace.c:1156
task_work_run+0x127/0x190 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0xb70/0x29a0 kernel/exit.c:890
do_group_exit+0x149/0x310 kernel/exit.c:1004
__do_sys_exit_group kernel/exit.c:1015 [inline]
__se_sys_exit_group kernel/exit.c:1013 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1013
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: 0033:0x7fb01d71ae99
Code: Unable to access opcode bytes at RIP 0x7fb01d71ae6f.
RSP: 002b:00007fff42a47c18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fb01d7b036a RCX: 00007fb01d71ae99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007fb01d7b030a
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff42a48ed0
R13: 00007fb01d7b030a R14: 000055558d3844e8 R15: 00007fff42a49fa0
---[ end trace 5cca9f346d556a16 ]---
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 132409067 P4D 132409067 PUD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 3100 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90001f47b00 EFLAGS: 00010246
RAX: 1ffffffff0a97e17 RBX: ffff888111d82660 RCX: ffffffff81b64f87
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888111d82660
RBP: ffffc90001f47b48 R08: 0000000000000003 R09: 00000000fffffffb
R10: dffffc0000000000 R11: ffffed10223b04d7 R12: 1ffff110223b04cc
R13: dffffc0000000000 R14: ffffffff854bf0b8 R15: ffff888111d826b8
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000125f06000 CR4: 00000000003506b0
Call Trace:
__dentry_kill+0xca/0x660 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+0x1af/0x210 fs/incfs/vfs.c:1997
deactivate_locked_super+0xa0/0x100 fs/super.c:335
deactivate_super+0xaf/0xe0 fs/super.c:366
cleanup_mnt+0x44f/0x500 fs/namespace.c:1149
__cleanup_mnt+0x19/0x20 fs/namespace.c:1156
task_work_run+0x127/0x190 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0xb70/0x29a0 kernel/exit.c:890
do_group_exit+0x149/0x310 kernel/exit.c:1004
__do_sys_exit_group kernel/exit.c:1015 [inline]
__se_sys_exit_group kernel/exit.c:1013 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1013
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: 0033:0x7fb01d71ae99
Code: Unable to access opcode bytes at RIP 0x7fb01d71ae6f.
RSP: 002b:00007fff42a47c18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fb01d7b036a RCX: 00007fb01d71ae99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007fb01d7b030a
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff42a48ed0
R13: 00007fb01d7b030a R14: 000055558d3844e8 R15: 00007fff42a49fa0
Modules linked in:
CR2: 0000000000000000
---[ end trace 5cca9f346d556a17 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90001f47b00 EFLAGS: 00010246
RAX: 1ffffffff0a97e17 RBX: ffff888111d82660 RCX: ffffffff81b64f87
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888111d82660
RBP: ffffc90001f47b48 R08: 0000000000000003 R09: 00000000fffffffb
R10: dffffc0000000000 R11: ffffed10223b04d7 R12: 1ffff110223b04cc
R13: dffffc0000000000 R14: ffffffff854bf0b8 R15: ffff888111d826b8
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000125f06000 CR4: 00000000003506b0