------------[ cut here ]------------
kernfs_put: syz2/pids.events: released with incorrect active_ref 0
WARNING: CPU: 1 PID: 15550 at fs/kernfs/dir.c:531 kernfs_put.part.0+0x433/0x540
Modules linked in:
CPU: 1 PID: 15550 Comm: kworker/1:1 Not tainted 5.19.0-rc4-next-20220701 #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 42 a7 ff 48 8b 14 24 44 89 f1 4c 89 fe 48 c7 c7 a0 58 72 84 e8 97 1c 6c 02 <0f> 0b e9 b9 fc ff ff 48 89 ef e8 8e b6 d9 ff e9 c1 fd ff ff e8 84
RSP: 0018:ffff88800f2f7bd8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff88801b870000 RSI: ffffffff812b6848 RDI: ffffed1001e5ef6d
RBP: ffff88800d34e038 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88800d34e000
R13: ffff888036d83bc8 R14: 0000000000000000 R15: ffff88803636bb18
FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd92d55fa0 CR3: 000000001b906000 CR4: 0000000000350ee0
Call Trace:
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
irq event stamp: 1098445
hardirqs last enabled at (1098455): [] __up_console_sem+0x78/0x80
hardirqs last disabled at (1098466): [] __up_console_sem+0x5d/0x80
softirqs last enabled at (1098024): [] __irq_exit_rcu+0x113/0x170
softirqs last disabled at (1097961): [] __irq_exit_rcu+0x113/0x170
---[ end trace 0000000000000000 ]---
==================================================================
BUG: KASAN: use-after-free in kernfs_notify+0x327/0x350
Read of size 2 at addr ffff88800d34e098 by task ksoftirqd/1/19
CPU: 1 PID: 19 Comm: ksoftirqd/1 Tainted: G W 5.19.0-rc4-next-20220701 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack_lvl+0x8b/0xb3
print_report.cold+0x5e/0x5e1
kasan_report+0xb1/0x1b0
kernfs_notify+0x327/0x350
cgroup_file_notify+0xf5/0x1a0
call_timer_fn+0x17d/0x5f0
__run_timers.part.0+0x65e/0xa50
run_timer_softirq+0xae/0x1a0
__do_softirq+0x1c8/0x8cc
run_ksoftirqd+0x2d/0x60
smpboot_thread_fn+0x66f/0xa00
kthread+0x2ed/0x3a0
ret_from_fork+0x22/0x30
Allocated by task 299:
kasan_save_stack+0x1e/0x40
__kasan_slab_alloc+0x66/0x80
kmem_cache_alloc+0x1b1/0x490
__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 15550:
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 ffff88800d34e000
which belongs to the cache kernfs_node_cache of size 168
The buggy address is located 152 bytes inside of
168-byte region [ffff88800d34e000, ffff88800d34e0a8)
The buggy address belongs to the physical page:
page:0000000056760c76 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xd34e
flags: 0x100000000000200(slab|node=0|zone=1)
raw: 0100000000000200 0000000000000000 dead000000000122 ffff8880080718c0
raw: 0000000000000000 0000000000110011 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88800d34df80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88800d34e000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88800d34e080: fb fb fb fb fb fc fc fc fc fc fc fc fc 00 00 00
^
ffff88800d34e100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88800d34e180: 00 00 fc fc fc fc fc fc fc fc 00 00 00 00 00 00
==================================================================
------------[ cut here ]------------
WARNING: CPU: 1 PID: 19 at fs/kernfs/dir.c:504 kernfs_get.part.0+0x69/0x80
Modules linked in:
CPU: 1 PID: 19 Comm: ksoftirqd/1 Tainted: G B W 5.19.0-rc4-next-20220701 #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
Code: 31 ff 89 ee e8 a8 43 a7 ff 85 ed 74 18 e8 cf 46 a7 ff be 04 00 00 00 48 89 df e8 52 be d9 ff f0 ff 03 5b 5d c3 e8 b7 46 a7 ff <0f> 0b eb df 48 89 df e8 fb ba d9 ff eb c6 66 0f 1f 84 00 00 00 00
RSP: 0018:ffff8880082b7b68 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff88800d34e000 RCX: 0000000000000100
RDX: ffff88800828d040 RSI: ffffffff819d2579 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001
R13: 1ffffffff0a01e40 R14: ffff88800d34e000 R15: ffff88800dcc9130
FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd92d55fa0 CR3: 000000001b910000 CR4: 0000000000350ee0
Call Trace:
kernfs_get+0x1b/0x30
kernfs_notify+0x180/0x350
cgroup_file_notify+0xf5/0x1a0
call_timer_fn+0x17d/0x5f0
__run_timers.part.0+0x65e/0xa50
run_timer_softirq+0xae/0x1a0
__do_softirq+0x1c8/0x8cc
run_ksoftirqd+0x2d/0x60
smpboot_thread_fn+0x66f/0xa00
kthread+0x2ed/0x3a0
ret_from_fork+0x22/0x30
irq event stamp: 7533499
hardirqs last enabled at (7533498): [] _raw_spin_unlock_irq+0x1f/0x40
hardirqs last disabled at (7533499): [] _raw_spin_lock_irqsave+0x4e/0x50
softirqs last enabled at (7533486): [] run_ksoftirqd+0x2d/0x60
softirqs last disabled at (7533491): [] run_ksoftirqd+0x2d/0x60
---[ end trace 0000000000000000 ]---