[syzbot] INFO: task hung in cgroup_can_fork

[syzbot] INFO: task hung in cgroup_can_fork

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    9eaa88c7036e Merge tag 'libata-5.16-rc6' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11872543b00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=fa556098924b78f0
dashboard link: https://syzkaller.appspot.com/bug?extid=304cbc9725238275b855
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=154716a3b00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=111e92dbb00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+304cbc9725238275b855@syzkaller.appspotmail.com

INFO: task syz-executor812:3663 blocked for more than 165 seconds.
      Not tainted 5.16.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor812 state:D stack:27552 pid: 3663 ppid:  3654 flags:0x00000000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4972 [inline]
 context_switch kernel/sched/core.c:4972 [inline] kernel/sched/core.c:6253
 __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 kernel/sched/core.c:6253
 schedule+0xd2/0x260 kernel/sched/core.c:6326 kernel/sched/core.c:6326
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6385 kernel/sched/core.c:6385
 __mutex_lock_common kernel/locking/mutex.c:680 [inline]
 __mutex_lock_common kernel/locking/mutex.c:680 [inline] kernel/locking/mutex.c:740
 __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:740 kernel/locking/mutex.c:740
 cgroup_css_set_fork kernel/cgroup/cgroup.c:6090 [inline]
 cgroup_css_set_fork kernel/cgroup/cgroup.c:6090 [inline] kernel/cgroup/cgroup.c:6206
 cgroup_can_fork+0x888/0xeb0 kernel/cgroup/cgroup.c:6206 kernel/cgroup/cgroup.c:6206
 copy_process+0x3636/0x75a0 kernel/fork.c:2292 kernel/fork.c:2292
 kernel_clone+0xe7/0xab0 kernel/fork.c:2582 kernel/fork.c:2582
 __do_sys_clone3+0x1ca/0x2e0 kernel/fork.c:2857 kernel/fork.c:2857
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_x64 arch/x86/entry/common.c:50 [inline] arch/x86/entry/common.c:80
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fbc074509a9
RSP: 002b:00007fbc074022f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 0000000000000031 RCX: 00007fbc074509a9
RDX: 00007fbc074509a9 RSI: 0000000000000058 RDI: 0000000020000080
RBP: 00007fbc074d8408 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbc074d8400
R13: 00007fbc074d840c R14: 00007fbc074a6074 R15: 0000000280000000
 </TASK>
INFO: task syz-executor812:3664 blocked for more than 172 seconds.
      Not tainted 5.16.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor812 state:D stack:27552 pid: 3664 ppid:     1 flags:0x00000000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4972 [inline]
 context_switch kernel/sched/core.c:4972 [inline] kernel/sched/core.c:6253
 __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 kernel/sched/core.c:6253
 schedule+0xd2/0x260 kernel/sched/core.c:6326 kernel/sched/core.c:6326
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6385 kernel/sched/core.c:6385
 __mutex_lock_common kernel/locking/mutex.c:680 [inline]
 __mutex_lock_common kernel/locking/mutex.c:680 [inline] kernel/locking/mutex.c:740
 __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:740 kernel/locking/mutex.c:740


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