------------[ cut here ]------------
kernfs_put: syz1/pids.events: released with incorrect active_ref 0
WARNING: CPU: 1 PID: 36498 at fs/kernfs/dir.c:531 kernfs_put.part.0+0x433/0x540
Modules linked in:
CPU: 1 PID: 36498 Comm: kworker/1:0 Not tainted 5.19.0-rc5-next-20220706 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Workqueue: events kernfs_notify_workfn
RIP: 0010:kernfs_put.part.0+0x433/0x540
Code: 03 80 3c 18 00 0f 85 ea 00 00 00 4d 8b 7d 38 e8 53 fc a6 ff 48 8b 14 24 44 89 f1 4c 89 fe 48 c7 c7 e0 5b 72 84 e8 13 aa 6c 02 <0f> 0b e9 b9 fc ff ff 48 89 ef e8 0e b3 d9 ff e9 c1 fd ff ff e8 04
RSP: 0018:ffff888044b07bd8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff888045ec5040 RSI: ffffffff812bd348 RDI: ffffed1008960f6d
RBP: ffff888044274eb8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff888044274e80
R13: ffff88801da64ae0 R14: 0000000000000000 R15: ffff8880203403c0
FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe0782e29c8 CR3: 00000000488f4000 CR4: 0000000000350ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
Call Trace:
kernfs_put+0x42/0x50
kernfs_notify_workfn+0x417/0x560
process_one_work+0xa0f/0x1690
------------[ cut here ]------------
WARNING: CPU: 0 PID: 43829 at fs/kernfs/dir.c:504 kernfs_get.part.0+0x69/0x80
worker_thread+0x637/0x1250
Modules linked in:
CPU: 0 PID: 43829 Comm: syz-executor.1 Not tainted 5.19.0-rc5-next-20220706 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RIP: 0010:kernfs_get.part.0+0x69/0x80
kthread+0x2ed/0x3a0
Code: 31 ff 89 ee e8 a8 fd a6 ff 85 ed 74 18 e8 cf 00 a7 ff be 04 00 00 00 48 89 df e8 d2 ba d9 ff f0 ff 03 5b 5d c3 e8 b7 00 a7 ff <0f> 0b eb df 48 89 df e8 7b b7 d9 ff eb c6 66 0f 1f 84 00 00 00 00
RSP: 0018:ffff888046c8fa40 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffff888044274e80 RCX: 0000000000000000
ret_from_fork+0x22/0x30
RDX: ffff888044865040 RSI: ffffffff819df849 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
irq event stamp: 465819
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001
R13: 1ffffffff0a01e40 R14: ffff888044274e80 R15: ffff88801887e930
hardirqs last enabled at (465831): [] asm_sysvec_apic_timer_interrupt+0x1b/0x20
FS: 0000555556be4400(0000) GS:ffff88806ce00000(0000) knlGS:0000000000000000
hardirqs last disabled at (465840): [] sysvec_apic_timer_interrupt+0xb/0xc0
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
softirqs last enabled at (465402): [] __irq_exit_rcu+0x113/0x170
CR2: 00007f5cba377000 CR3: 00000000488f4000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
softirqs last disabled at (465299): [] __irq_exit_rcu+0x113/0x170
DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
Call Trace:
kernfs_get+0x1b/0x30
---[ end trace 0000000000000000 ]---
kernfs_notify+0x180/0x350
==================================================================
cgroup_file_notify+0xf5/0x1a0
BUG: KASAN: use-after-free in llist_del_first+0x89/0xa0
pids_can_fork+0x22f/0x370
Read of size 8 at addr ffff888044274f00 by task kworker/1:0/36498
CPU: 1 PID: 36498 Comm: kworker/1:0 Tainted: G W 5.19.0-rc5-next-20220706 #1
cgroup_can_fork+0x332/0x11b0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
copy_process+0x4023/0x6d60
Workqueue: events kernfs_notify_workfn
Call Trace:
kernel_clone+0xe7/0xa60
dump_stack_lvl+0x8b/0xb3
print_report.cold+0x5e/0x5e1
kasan_report+0xb1/0x1b0
__do_sys_clone+0xba/0x100
llist_del_first+0x89/0xa0
kernfs_notify_workfn+0x78/0x560
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fe07a56cf41
process_one_work+0xa0f/0x1690
Code: 48 85 ff 74 3d 48 85 f6 74 38 48 83 ee 10 48 89 4e 08 48 89 3e 48 89 d7 4c 89 c2 4d 89 c8 4c 8b 54 24 08 b8 38 00 00 00 0f 05 <48> 85 c0 7c 13 74 01 c3 31 ed 58 5f ff d0 48 89 c7 b8 3c 00 00 00
RSP: 002b:00007ffc7b617ba8 EFLAGS: 00000206
ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fe077ac0700 RCX: 00007fe07a56cf41
worker_thread+0x637/0x1250
RDX: 00007fe077ac09d0 RSI: 00007fe077ac02f0 RDI: 00000000003d0f00
RBP: 00007ffc7b617de0 R08: 00007fe077ac0700 R09: 00007fe077ac0700
R10: 00007fe077ac09d0 R11: 0000000000000206 R12: 00007ffc7b617c5e
kthread+0x2ed/0x3a0
R13: 00007ffc7b617c5f R14: 00007fe077ac0300 R15: 0000555556be5d50
ret_from_fork+0x22/0x30
irq event stamp: 8738
hardirqs last enabled at (8737): [] _raw_spin_unlock_irq+0x1f/0x40
Allocated by task 544:
hardirqs last disabled at (8738): [] _raw_spin_lock_irqsave+0x4e/0x50
kasan_save_stack+0x1e/0x40
softirqs last enabled at (8714): [] fpu_clone+0x3be/0xb00
__kasan_slab_alloc+0x66/0x80
softirqs last disabled at (8712): [] fpu_clone+0x331/0xb00
kmem_cache_alloc+0x1b1/0x490
---[ end trace 0000000000000000 ]---
__kernfs_new_node+0xd4/0x8b0
kernfs_new_node+0x93/0x120
__kernfs_create_file+0x51/0x350
cgroup_addrm_files+0x3e2/0x9d0
css_populate_dir+0x19b/0x450
cgroup_apply_control_enable+0x3ae/0xa40
cgroup_mkdir+0x824/0x11f0
kernfs_iop_mkdir+0x149/0x1d0
vfs_mkdir+0x417/0x6a0
do_mkdirat+0x17b/0x2e0
__x64_sys_mkdir+0xf2/0x140
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x46/0xb0
Freed by task 36498:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_set_free_info+0x20/0x30
__kasan_slab_free+0x108/0x190
kmem_cache_free+0xfb/0x600
kernfs_put.part.0+0x2c7/0x540
kernfs_put+0x42/0x50
kernfs_notify_workfn+0x417/0x560
process_one_work+0xa0f/0x1690
worker_thread+0x637/0x1250
kthread+0x2ed/0x3a0
ret_from_fork+0x22/0x30
The buggy address belongs to the object at ffff888044274e80
which belongs to the cache kernfs_node_cache of size 168
The buggy address is located 128 bytes inside of
168-byte region [ffff888044274e80, ffff888044274f28)
The buggy address belongs to the physical page:
page:00000000dc9f4cc5 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x44274
flags: 0x100000000000200(slab|node=0|zone=1)
raw: 0100000000000200 0000000000000000 dead000000000122 ffff8880080358c0
raw: 0000000000000000 0000000000110011 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888044274e00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
ffff888044274e80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888044274f00: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc
^
ffff888044274f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888044275000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
ata2.00: qc timeout (cmd 0xa0)
ata2: found unknown device (class 0)
----------------
Code disassembly (best guess):
0: 48 85 ff test %rdi,%rdi
3: 74 3d je 0x42
5: 48 85 f6 test %rsi,%rsi
8: 74 38 je 0x42
a: 48 83 ee 10 sub $0x10,%rsi
e: 48 89 4e 08 mov %rcx,0x8(%rsi)
12: 48 89 3e mov %rdi,(%rsi)
15: 48 89 d7 mov %rdx,%rdi
18: 4c 89 c2 mov %r8,%rdx
1b: 4d 89 c8 mov %r9,%r8
1e: 4c 8b 54 24 08 mov 0x8(%rsp),%r10
23: b8 38 00 00 00 mov $0x38,%eax
28: 0f 05 syscall
* 2a: 48 85 c0 test %rax,%rax <-- trapping instruction
2d: 7c 13 jl 0x42
2f: 74 01 je 0x32
31: c3 retq
32: 31 ed xor %ebp,%ebp
34: 58 pop %rax
35: 5f pop %rdi
36: ff d0 callq *%rax
38: 48 89 c7 mov %rax,%rdi
3b: b8 3c 00 00 00 mov $0x3c,%eax