R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffda24ccb0
R13: 00007fe05b034ccb R14: 0000555589b2c4e8 R15: 00007fffda24dd80
---[ end trace 0000000000000000 ]---
==================================================================
BUG: KASAN: use-after-free in fast_dput+0x1e0/0x290 fs/dcache.c:778
Read of size 4 at addr ffff8881614dd110 by task syz-executor/16262
CPU: 0 PID: 16262 Comm: syz-executor Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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+0x1e0/0x290 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+0x1af/0x210 fs/incfs/vfs.c:2005
deactivate_locked_super+0xb5/0x120 fs/super.c:336
deactivate_super+0xaf/0xe0 fs/super.c:367
cleanup_mnt+0x45e/0x4e0 fs/namespace.c:1192
__cleanup_mnt+0x19/0x20 fs/namespace.c:1199
task_work_run+0x1e1/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xb0d/0x29f0 kernel/exit.c:896
do_group_exit+0x21b/0x2e0 kernel/exit.c:1040
__do_sys_exit_group kernel/exit.c:1051 [inline]
__se_sys_exit_group kernel/exit.c:1049 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1049
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: 0033:0x7fe05af9e1d9
Code: Unable to access opcode bytes at 0x7fe05af9e1af.
RSP: 002b:00007fffda24b9f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fe05b034d2b RCX: 00007fe05af9e1d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007fe05b034ccb
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffda24ccb0
R13: 00007fe05b034ccb R14: 0000555589b2c4e8 R15: 00007fffda24dd80
Allocated by task 21003:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_alloc_info+0x1f/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+0x34/0x6d0 fs/dcache.c:1774
d_alloc fs/dcache.c:1854 [inline]
d_alloc_parallel+0xe2/0x1280 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+0x4c/0x1f0 fs/incfs/vfs.c:477
incfs_mount_fs+0x42f/0x890 fs/incfs/vfs.c:1892
legacy_get_tree+0xfe/0x1a0 fs/fs_context.c:632
vfs_get_tree+0x9a/0x270 fs/super.c:1578
do_new_mount+0x251/0xb40 fs/namespace.c:3081
path_mount+0x640/0xfd0 fs/namespace.c:3411
do_mount fs/namespace.c:3424 [inline]
__do_sys_mount fs/namespace.c:3632 [inline]
__se_sys_mount+0x320/0x390 fs/namespace.c:3609
__x64_sys_mount+0xbf/0xd0 fs/namespace.c:3609
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 21026:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x2b/0x40 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+0x52b/0xc30 kernel/rcu/tree.c:2297
rcu_core+0x486/0xf00 kernel/rcu/tree.c:2557
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2574
handle_softirqs+0x1d7/0x600 kernel/softirq.c:642
__do_softirq kernel/softirq.c:680 [inline]
invoke_softirq kernel/softirq.c:497 [inline]
__irq_exit_rcu+0x52/0xf0 kernel/softirq.c:729
irq_exit_rcu+0x9/0x10 kernel/softirq.c:741
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691
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/0xf50 kernel/rcu/tree.c:2926
dentry_free+0xbd/0x150 fs/dcache.c:-1
__dentry_kill+0x535/0x680 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+0x1af/0x210 fs/incfs/vfs.c:2005
deactivate_locked_super+0xb5/0x120 fs/super.c:336
deactivate_super+0xaf/0xe0 fs/super.c:367
cleanup_mnt+0x45e/0x4e0 fs/namespace.c:1192
__cleanup_mnt+0x19/0x20 fs/namespace.c:1199
task_work_run+0x1e1/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xb0d/0x29f0 kernel/exit.c:896
do_group_exit+0x21b/0x2e0 kernel/exit.c:1040
__do_sys_exit_group kernel/exit.c:1051 [inline]
__se_sys_exit_group kernel/exit.c:1049 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1049
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
The buggy address belongs to the object at ffff8881614dd110
which belongs to the cache dentry of size 208
The buggy address is located 0 bytes inside of
208-byte region [ffff8881614dd110, ffff8881614dd1e0)
The buggy address belongs to the physical page:
page:ffffea0005853740 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1614dd
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 dead000000000122 ffff8881001edc80
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 21003, tgid 21002 (syz.3.4181), ts 630291192915, free_ts 594991478946
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2673
prep_new_page+0x1c/0x110 mm/page_alloc.c:2680
get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4587
__alloc_pages+0x1fa/0x610 mm/page_alloc.c:5931
alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
allocate_slab mm/slub.c:1967 [inline]
new_slab+0x98/0x3e0 mm/slub.c:2020
___slab_alloc+0x70f/0xb70 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+0x34/0x6d0 fs/dcache.c:1774
d_alloc_pseudo+0x1d/0x70 fs/dcache.c:1906
alloc_file_pseudo+0xe0/0x200 fs/file_table.c:265
__shmem_file_setup+0x1df/0x2b0 mm/shmem.c:4264
shmem_file_setup+0x2f/0x40 mm/shmem.c:4294
__do_sys_memfd_create mm/memfd.c:321 [inline]
__se_sys_memfd_create+0x1de/0x3c0 mm/memfd.c:266
__x64_sys_memfd_create+0x5b/0x70 mm/memfd.c:266
page last free stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
free_pages_prepare mm/page_alloc.c:1581 [inline]
free_pcp_prepare mm/page_alloc.c:1655 [inline]
free_unref_page_prepare+0x81b/0x820 mm/page_alloc.c:3622
free_unref_page+0x93/0x530 mm/page_alloc.c:3720
free_the_page mm/page_alloc.c:863 [inline]
__free_pages+0x67/0x100 mm/page_alloc.c:6021
__free_slab+0xc7/0x1a0 mm/slub.c:2044
free_slab mm/slub.c:2059 [inline]
discard_slab+0x29/0x40 mm/slub.c:2065
__slab_free+0x201/0x280 mm/slub.c:3625
do_slab_free mm/slub.c:3666 [inline]
___cache_free+0xbf/0xd0 mm/slub.c:3722
qlink_free mm/kasan/quarantine.c:168 [inline]
qlist_free_all+0xc6/0x140 mm/kasan/quarantine.c:187
kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:294
__kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:311
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]
kmem_cache_alloc_node+0x179/0x330 mm/slub.c:3429
__alloc_skb+0xe8/0x4a0 net/core/skbuff.c:508
alloc_skb include/linux/skbuff.h:1322 [inline]
nlmsg_new include/net/netlink.h:987 [inline]
rtmsg_ifinfo_build_skb+0x75/0x180 net/core/rtnetlink.c:3970
unregister_netdevice_many+0x10e4/0x1910 net/core/dev.c:11009
ip6_tnl_exit_batch_net+0x3ee/0x440 net/ipv6/ip6_tunnel.c:2302
Memory state around the buggy address:
ffff8881614dd000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8881614dd080: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
>ffff8881614dd100: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881614dd180: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff8881614dd200: fc fc fc fc 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
------------[ cut here ]------------
WARNING: CPU: 0 PID: 16262 at fs/dcache.c:794 fast_dput+0x207/0x290 fs/dcache.c:794
Modules linked in:
CPU: 0 PID: 16262 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:fast_dput+0x207/0x290 fs/dcache.c:794
Code: 99 f1 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 93 99 f1 ff e9 94 fe ff ff e8 e9 0c ac 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:ffffc90000b67af0 EFLAGS: 00010293
RAX: ffffffff81c56157 RBX: ffff8881614dd110 RCX: ffff888114b8e540
RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001
RBP: ffffc90000b67b18 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200016cf50 R12: 00000000ffffff80
R13: dffffc0000000000 R14: ffff8881614dd168 R15: 1ffff1102c29ba2d
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe10a158060 CR3: 000000000700f000 CR4: 00000000003506b0
DR0: 000000000000000c DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 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+0x1af/0x210 fs/incfs/vfs.c:2005
deactivate_locked_super+0xb5/0x120 fs/super.c:336
deactivate_super+0xaf/0xe0 fs/super.c:367
cleanup_mnt+0x45e/0x4e0 fs/namespace.c:1192
__cleanup_mnt+0x19/0x20 fs/namespace.c:1199
task_work_run+0x1e1/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xb0d/0x29f0 kernel/exit.c:896
do_group_exit+0x21b/0x2e0 kernel/exit.c:1040
__do_sys_exit_group kernel/exit.c:1051 [inline]
__se_sys_exit_group kernel/exit.c:1049 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1049
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: 0033:0x7fe05af9e1d9
Code: Unable to access opcode bytes at 0x7fe05af9e1af.
RSP: 002b:00007fffda24b9f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fe05b034d2b RCX: 00007fe05af9e1d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 0000000000000000 R09: 00007fe05b034ccb
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffda24ccb0
R13: 00007fe05b034ccb R14: 0000555589b2c4e8 R15: 00007fffda24dd80
---[ end trace 0000000000000000 ]---