==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:72 [inline]
BUG: KASAN: use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
BUG: KASAN: use-after-free in kernfs_get+0x21/0x90 fs/kernfs/dir.c:525
Read of size 4 at addr ffff88812519bc80 by task kworker/0:5/11708
CPU: 0 PID: 11708 Comm: kworker/0:5 Not tainted 6.1.128-syzkaller-00014-g33c9d4844afc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events flush_stashed_error_work
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:316 [inline]
print_report+0x158/0x4e0 mm/kasan/report.c:427
kasan_report+0x13c/0x170 mm/kasan/report.c:531
kasan_check_range+0x294/0x2a0 mm/kasan/generic.c:189
__kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31
instrument_atomic_read include/linux/instrumented.h:72 [inline]
atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
kernfs_get+0x21/0x90 fs/kernfs/dir.c:525
sysfs_notify+0x9a/0xd0 fs/sysfs/file.c:187
ext4_notify_error_sysfs+0x25/0x30 fs/ext4/sysfs.c:518
flush_stashed_error_work+0x2fe/0x320
process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299
worker_thread+0xa60/0x1260 kernel/workqueue.c:2446
kthread+0x26d/0x300 kernel/kthread.c:386
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Allocated by task 30598:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:333
kasan_slab_alloc include/linux/kasan.h:202 [inline]
slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768
slab_alloc_node mm/slub.c:3421 [inline]
slab_alloc mm/slub.c:3431 [inline]
__kmem_cache_alloc_lru mm/slub.c:3438 [inline]
kmem_cache_alloc+0x175/0x320 mm/slub.c:3447
kmem_cache_zalloc include/linux/slab.h:689 [inline]
__kernfs_new_node+0xdb/0x700 fs/kernfs/dir.c:614
kernfs_new_node+0x130/0x230 fs/kernfs/dir.c:690
kernfs_create_dir_ns+0x44/0x130 fs/kernfs/dir.c:1046
sysfs_create_dir_ns+0x185/0x390 fs/sysfs/dir.c:59
create_dir lib/kobject.c:63 [inline]
kobject_add_internal+0x635/0xbf0 lib/kobject.c:231
kobject_add_varg lib/kobject.c:366 [inline]
kobject_init_and_add+0x120/0x190 lib/kobject.c:449
ext4_register_sysfs+0xbf/0x2c0 fs/ext4/sysfs.c:531
__ext4_fill_super fs/ext4/super.c:5486 [inline]
ext4_fill_super+0x796e/0x8450 fs/ext4/super.c:5641
get_tree_bdev+0x440/0x680 fs/super.c:1368
ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5671
vfs_get_tree+0x88/0x290 fs/super.c:1575
do_new_mount+0x2ba/0xb30 fs/namespace.c:3056
path_mount+0x671/0x1070 fs/namespace.c:3386
do_mount fs/namespace.c:3399 [inline]
__do_sys_mount fs/namespace.c:3607 [inline]
__se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3584
__x64_sys_mount+0xbf/0xd0 fs/namespace.c:3584
x64_sys_call+0x49d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Freed by task 26839:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516
____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241
__kasan_slab_free+0x11/0x20 mm/kasan/common.c:249
kasan_slab_free include/linux/kasan.h:178 [inline]
slab_free_hook mm/slub.c:1745 [inline]
slab_free_freelist_hook mm/slub.c:1771 [inline]
slab_free mm/slub.c:3686 [inline]
kmem_cache_free+0x291/0x560 mm/slub.c:3711
kernfs_put+0x392/0x520 fs/kernfs/dir.c:568
sysfs_put include/linux/sysfs.h:657 [inline]
__kobject_del+0x10f/0x300 lib/kobject.c:597
kobject_del+0x45/0x60 lib/kobject.c:619
ext4_unregister_sysfs+0x91/0xa0 fs/ext4/sysfs.c:565
ext4_put_super+0x7d/0xd60 fs/ext4/super.c:1216
generic_shutdown_super+0x14f/0x370 fs/super.c:503
kill_block_super+0x7e/0xe0 fs/super.c:1472
deactivate_locked_super+0xad/0x110 fs/super.c:334
deactivate_super+0xbe/0xf0 fs/super.c:365
cleanup_mnt+0x485/0x510 fs/namespace.c:1186
__cleanup_mnt+0x19/0x20 fs/namespace.c:1193
task_work_run+0x24d/0x2e0 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0x94/0xa0 kernel/entry/common.c:177
exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x26/0x130 kernel/entry/common.c:303
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
The buggy address belongs to the object at ffff88812519bc80
which belongs to the cache kernfs_node_cache of size 136
The buggy address is located 0 bytes inside of
136-byte region [ffff88812519bc80, ffff88812519bd08)
The buggy address belongs to the physical page:
page:ffffea00049466c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12519b
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 dead000000000001 ffff8881002abe00
raw: 0000000000000000 0000000000140014 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 20300, tgid 20300 (syz-executor), ts 1973527472088, free_ts 1973485870909
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x213/0x220 mm/page_alloc.c:2637
prep_new_page+0x1b/0x110 mm/page_alloc.c:2644
get_page_from_freelist+0x3a98/0x3b10 mm/page_alloc.c:4539
__alloc_pages+0x234/0x610 mm/page_alloc.c:5837
alloc_slab_page+0x6c/0xf0
allocate_slab mm/slub.c:1962 [inline]
new_slab+0x90/0x3e0 mm/slub.c:2015
___slab_alloc+0x6f9/0xb80 mm/slub.c:3203
__slab_alloc+0x5d/0xa0 mm/slub.c:3302
slab_alloc_node mm/slub.c:3387 [inline]
slab_alloc mm/slub.c:3431 [inline]
__kmem_cache_alloc_lru mm/slub.c:3438 [inline]
kmem_cache_alloc+0x1be/0x320 mm/slub.c:3447
kmem_cache_zalloc include/linux/slab.h:689 [inline]
__kernfs_new_node+0xdb/0x700 fs/kernfs/dir.c:614
kernfs_new_node+0x130/0x230 fs/kernfs/dir.c:690
__kernfs_create_file+0x4a/0x270 fs/kernfs/file.c:1049
sysfs_add_file_mode_ns+0x1c8/0x270 fs/sysfs/file.c:294
create_files fs/sysfs/group.c:64 [inline]
internal_create_group+0x545/0xed0 fs/sysfs/group.c:148
internal_create_groups fs/sysfs/group.c:188 [inline]
sysfs_create_groups+0x5b/0x130 fs/sysfs/group.c:214
create_dir lib/kobject.c:68 [inline]
kobject_add_internal+0x676/0xbf0 lib/kobject.c:231
page last free stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
free_pages_prepare mm/page_alloc.c:1545 [inline]
free_pcp_prepare mm/page_alloc.c:1619 [inline]
free_unref_page_prepare+0x9f1/0xa00 mm/page_alloc.c:3581
free_unref_page+0xb2/0x5c0 mm/page_alloc.c:3677
free_the_page mm/page_alloc.c:830 [inline]
__free_pages+0x61/0xf0 mm/page_alloc.c:5926
__vunmap+0x9c6/0xb80 mm/vmalloc.c:2729
__vfree mm/vmalloc.c:2778 [inline]
vfree+0x5c/0x80 mm/vmalloc.c:2809
kvfree+0x26/0x40 mm/util.c:637
__vunmap+0xab8/0xb80 mm/vmalloc.c:2735
__vfree mm/vmalloc.c:2778 [inline]
vfree+0x5c/0x80 mm/vmalloc.c:2809
kcov_put kernel/kcov.c:437 [inline]
kcov_close+0x2b/0x50 kernel/kcov.c:533
__fput+0x1e5/0x870 fs/file_table.c:320
____fput+0x15/0x20 fs/file_table.c:348
task_work_run+0x24d/0x2e0 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xbd0/0x2b80 kernel/exit.c:877
do_group_exit+0x21a/0x2d0 kernel/exit.c:1027
get_signal+0x169d/0x1820 kernel/signal.c:2889
arch_do_signal_or_restart+0xb0/0x16f0 arch/x86/kernel/signal.c:871
Memory state around the buggy address:
ffff88812519bb80: fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 00
ffff88812519bc00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff88812519bc80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88812519bd00: fb fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00
ffff88812519bd80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
==================================================================
general protection fault, probably for non-canonical address 0xe0f77c2a80000d24: 0000 [#1] PREEMPT SMP KASAN
KASAN: maybe wild-memory-access in range [0x07bc015400006920-0x07bc015400006927]
CPU: 0 PID: 11708 Comm: kworker/0:5 Tainted: G B 6.1.128-syzkaller-00014-g33c9d4844afc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events flush_stashed_error_work
RIP: 0010:kernfs_root fs/kernfs/kernfs-internal.h:68 [inline]
RIP: 0010:kernfs_find_and_get_ns+0x52/0x110 fs/kernfs/dir.c:903
Code: 08 48 89 f8 48 c1 e8 03 42 80 3c 30 00 74 05 e8 c4 bb d3 ff 49 8b 5d 08 48 85 db 49 0f 44 dd 48 83 c3 50 48 89 d8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 df e8 9f bb d3 ff 4c 8b 33 49 83 c6 60
RSP: 0018:ffffc90000a97c68 EFLAGS: 00010207
RAX: 00f7802a80000d24 RBX: 07bc015400006927 RCX: ffffffff81e9796c
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88812519bc88
RBP: ffffc90000a97c90 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: ffffffff85d4d920
R13: ffff88812519bc80 R14: dffffc0000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555620004a8 CR3: 000000000700f000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kernfs_find_and_get include/linux/kernfs.h:614 [inline]
sysfs_notify+0x73/0xd0 fs/sysfs/file.c:190
ext4_notify_error_sysfs+0x25/0x30 fs/ext4/sysfs.c:518
flush_stashed_error_work+0x2fe/0x320
process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299
worker_thread+0xa60/0x1260 kernel/workqueue.c:2446
kthread+0x26d/0x300 kernel/kthread.c:386
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kernfs_root fs/kernfs/kernfs-internal.h:68 [inline]
RIP: 0010:kernfs_find_and_get_ns+0x52/0x110 fs/kernfs/dir.c:903
Code: 08 48 89 f8 48 c1 e8 03 42 80 3c 30 00 74 05 e8 c4 bb d3 ff 49 8b 5d 08 48 85 db 49 0f 44 dd 48 83 c3 50 48 89 d8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 df e8 9f bb d3 ff 4c 8b 33 49 83 c6 60
RSP: 0018:ffffc90000a97c68 EFLAGS: 00010207
RAX: 00f7802a80000d24 RBX: 07bc015400006927 RCX: ffffffff81e9796c
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88812519bc88
RBP: ffffc90000a97c90 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: ffffffff85d4d920
R13: ffff88812519bc80 R14: dffffc0000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555620004a8 CR3: 000000010feb0000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 08 48 89 or %cl,-0x77(%rax)
3: f8 clc
4: 48 c1 e8 03 shr $0x3,%rax
8: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1)
d: 74 05 je 0x14
f: e8 c4 bb d3 ff call 0xffd3bbd8
14: 49 8b 5d 08 mov 0x8(%r13),%rbx
18: 48 85 db test %rbx,%rbx
1b: 49 0f 44 dd cmove %r13,%rbx
1f: 48 83 c3 50 add $0x50,%rbx
23: 48 89 d8 mov %rbx,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 48 89 df mov %rbx,%rdi
34: e8 9f bb d3 ff call 0xffd3bbd8
39: 4c 8b 33 mov (%rbx),%r14
3c: 49 83 c6 60 add $0x60,%r14