syzbot


INFO: task hung in cgroup_can_fork

Status: upstream: reported on 2024/10/22 16:24
Reported-by: syzbot+ff14c0010f9d99ac3114@syzkaller.appspotmail.com
First crash: 44d, last: 44d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in cgroup_can_fork 1 62d 62d 0/3 upstream: reported on 2024/10/05 02:23
upstream INFO: task hung in cgroup_can_fork cgroups C error error 6 1059d 1079d 0/28 auto-obsoleted due to no activity on 2023/09/02 21:24

Sample crash report:
INFO: task kworker/u4:0:9 blocked for more than 143 seconds.
      Not tainted 6.1.114-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:0    state:D stack:22776 pid:9     ppid:2      flags:0x00004000
Workqueue: events_unbound call_usermodehelper_exec_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 cgroup_css_set_fork kernel/cgroup/cgroup.c:6404 [inline]
 cgroup_can_fork+0xb87/0xc70 kernel/cgroup/cgroup.c:6533
 copy_process+0x241c/0x4060 kernel/fork.c:2368
 kernel_clone+0x222/0x920 kernel/fork.c:2679
 user_mode_thread+0x12e/0x190 kernel/fork.c:2755
 call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
 call_usermodehelper_exec_work+0x93/0x220 kernel/umh.c:167
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
INFO: task udevd:3094 blocked for more than 143 seconds.
      Not tainted 6.1.114-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:23176 pid:3094  ppid:1      flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 cgroup_css_set_fork kernel/cgroup/cgroup.c:6404 [inline]
 cgroup_can_fork+0xb87/0xc70 kernel/cgroup/cgroup.c:6533
 copy_process+0x241c/0x4060 kernel/fork.c:2368
 kernel_clone+0x222/0x920 kernel/fork.c:2679
 __do_sys_clone kernel/fork.c:2820 [inline]
 __se_sys_clone kernel/fork.c:2804 [inline]
 __x64_sys_clone+0x231/0x280 kernel/fork.c:2804
 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
RIP: 0033:0x7f201fefca12
RSP: 002b:00007ffc8f0507a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000564bb027ec01 RCX: 00007f201fefca12
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000006 R08: 0000000000000000 R09: 0000564bb025d910
R10: 00007f20203caf50 R11: 0000000000000246 R12: 0000564bb0273a20
R13: 0000000000000000 R14: 0000000000000000 R15: 0000564bb025d910
 </TASK>
INFO: task udevd:3635 blocked for more than 143 seconds.
      Not tainted 6.1.114-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:24960 pid:3635  ppid:3094   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 exit_signals+0x435/0x530 kernel/signal.c:2962
 do_exit+0x69f/0x26a0 kernel/exit.c:827
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 __do_sys_exit_group kernel/exit.c:1032 [inline]
 __se_sys_exit_group kernel/exit.c:1030 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030
 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
RIP: 0033:0x7f201fefca90
RSP: 002b:00007ffc8f0508a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f201fefca90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000007 R09: d0b87b45c1f0ec84
R10: 00000000ffffffff R11: 0000000000000202 R12: 0000564bb0283780
R13: 00007ffc8f0508e8 R14: 0000000000000001 R15: 0000564bb025d910
 </TASK>
INFO: task udevd:3637 blocked for more than 144 seconds.
      Not tainted 6.1.114-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:26184 pid:3637  ppid:3094   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 exit_signals+0x435/0x530 kernel/signal.c:2962
 do_exit+0x69f/0x26a0 kernel/exit.c:827
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 __do_sys_exit_group kernel/exit.c:1032 [inline]
 __se_sys_exit_group kernel/exit.c:1030 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030
 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
RIP: 0033:0x7f201fefca90
RSP: 002b:00007ffc8f0508a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f201fefca90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000007 R09: d0b87b45c1f0ec84
R10: 00000000ffffffff R11: 0000000000000202 R12: 0000564bb0283f70
R13: 00007ffc8f0508e8 R14: 0000000000000001 R15: 0000564bb025d910
 </TASK>
INFO: task syz-executor:3641 blocked for more than 144 seconds.
      Not tainted 6.1.114-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:23880 pid:3641  ppid:3632   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 exit_signals+0x435/0x530 kernel/signal.c:2962
 do_exit+0x69f/0x26a0 kernel/exit.c:827
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 get_signal+0x16f7/0x17d0 kernel/signal.c:2870
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f793fd74213
RSP: 002b:00007ffef94e5db8 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 0000000000000e3f RCX: 00007f793fd74213
RDX: 0000000040000000 RSI: 00007ffef94e5dcc RDI: 00000000ffffffff
RBP: 00007ffef94e5dcc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000c
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
INFO: task udevd:3783 blocked for more than 144 seconds.
      Not tainted 6.1.114-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:25328 pid:3783  ppid:3094   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 exit_signals+0x435/0x530 kernel/signal.c:2962
 do_exit+0x69f/0x26a0 kernel/exit.c:827
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 __do_sys_exit_group kernel/exit.c:1032 [inline]
 __se_sys_exit_group kernel/exit.c:1030 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030
 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
RIP: 0033:0x7f201fefca90
RSP: 002b:00007ffc8f0508a8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f201fefca90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000007 R09: d0b87b45c1f0ec84
R10: 00000000ffffffff R11: 0000000000000206 R12: 0000564bb027cef0
R13: 00007ffc8f0508e8 R14: 0000000000000001 R15: 0000564bb025d910
 </TASK>
INFO: task udevd:3787 blocked for more than 144 seconds.
      Not tainted 6.1.114-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:26184 pid:3787  ppid:3094   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 exit_signals+0x435/0x530 kernel/signal.c:2962
 do_exit+0x69f/0x26a0 kernel/exit.c:827
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 __do_sys_exit_group kernel/exit.c:1032 [inline]
 __se_sys_exit_group kernel/exit.c:1030 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030
 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
RIP: 0033:0x7f201fefca90
RSP: 002b:00007ffc8f0508a8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f201fefca90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000007 R09: d0b87b45c1f0ec84
R10: 00000000ffffffff R11: 0000000000000206 R12: 0000564bb026ee10
R13: 00007ffc8f0508e8 R14: 0000000000000001 R15: 0000564bb025d910
 </TASK>
INFO: task udevd:3788 blocked for more than 145 seconds.
      Not tainted 6.1.114-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:26184 pid:3788  ppid:3094   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 exit_signals+0x435/0x530 kernel/signal.c:2962
 do_exit+0x69f/0x26a0 kernel/exit.c:827
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 __do_sys_exit_group kernel/exit.c:1032 [inline]
 __se_sys_exit_group kernel/exit.c:1030 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030
 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
RIP: 0033:0x7f201fefca90
RSP: 002b:00007ffc8f0508a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f201fefca90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000007 R09: d0b87b45c1f0ec84
R10: 00000000ffffffff R11: 0000000000000202 R12: 0000564bb0280d80
R13: 00007ffc8f0508e8 R14: 0000000000000001 R15: 0000564bb025d910
 </TASK>
INFO: task udevd:3789 blocked for more than 145 seconds.
      Not tainted 6.1.114-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:26184 pid:3789  ppid:3094   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 exit_signals+0x435/0x530 kernel/signal.c:2962
 do_exit+0x69f/0x26a0 kernel/exit.c:827
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 __do_sys_exit_group kernel/exit.c:1032 [inline]
 __se_sys_exit_group kernel/exit.c:1030 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030
 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
RIP: 0033:0x7f201fefca90
RSP: 002b:00007ffc8f0508a8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f201fefca90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000007 R09: d0b87b45c1f0ec84
R10: 00000000ffffffff R11: 0000000000000206 R12: 0000564bb026f060
R13: 00007ffc8f0508e8 R14: 0000000000000001 R15: 0000564bb025d910
 </TASK>
INFO: task syz-executor:4348 blocked for more than 145 seconds.
      Not tainted 6.1.114-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21112 pid:4348  ppid:4323   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 rwsem_down_write_slowpath+0xea1/0x14b0 kernel/locking/rwsem.c:1189
 mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 mpol_rebind_mm+0xe4/0x390 mm/mempolicy.c:386
 cpuset_attach+0x29b/0x560 kernel/cgroup/cpuset.c:2663
 cgroup_migrate_execute+0x7e3/0x1060 kernel/cgroup/cgroup.c:2639
 cgroup_attach_task+0x614/0x970 kernel/cgroup/cgroup.c:2930
 __cgroup1_procs_write+0x2ef/0x460 kernel/cgroup/cgroup-v1.c:522
 cgroup_file_write+0x2c6/0x6c0 kernel/cgroup/cgroup.c:4081
 kernfs_fop_write_iter+0x3a2/0x4f0 fs/kernfs/file.c:334
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x857/0xbc0 fs/read_write.c:584
 ksys_write+0x19c/0x2c0 fs/read_write.c:637
 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
RIP: 0033:0x7f26f8b7cadf
RSP: 002b:00007ffdc1694480 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f26f8b7cadf
RDX: 0000000000000001 RSI: 00007ffdc16944d0 RDI: 0000000000000003
RBP: 00007ffdc1694a30 R08: 0000000000000000 R09: 00007ffdc16942d7
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007ffdc16944d0 R14: 00007ffdc16949f0 R15: 00007ffdc1694a30
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u4:0/9:
 #0: ffff888017c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc900000e7d20 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x241c/0x4060 kernel/fork.c:2368
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32b1d0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d32b9d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510
1 lock held by klogd/3083:
 #0: ffff8880b8e3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
1 lock held by udevd/3094:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x241c/0x4060 kernel/fork.c:2368
2 locks held by getty/3396:
 #0: ffff88814b51c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198
1 lock held by udevd/3635:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
1 lock held by udevd/3637:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
1 lock held by syz-executor/3641:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
2 locks held by syz-executor/3647:
 #0: ffffffff8d3c5910 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:592 [inline]
 #0: ffffffff8d3c5910 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1540 [inline]
 #0: ffffffff8d3c5910 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x3cb/0x1990 kernel/fork.c:1589
 #1: ffff88807de01f58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff88807de01f58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:593 [inline]
 #1: ffff88807de01f58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1540 [inline]
 #1: ffff88807de01f58 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x3e5/0x1990 kernel/fork.c:1589
1 lock held by udevd/3783:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
1 lock held by udevd/3787:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
1 lock held by udevd/3788:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
1 lock held by udevd/3789:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
7 locks held by syz-executor/4348:
 #0: ffff88802d7fa460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x269/0xbc0 fs/read_write.c:580
 #1: ffff8880784d5088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x4f0 fs/kernfs/file.c:325
 #2: ffffffff8d3535e8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:442 [inline]
 #2: ffffffff8d3535e8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xe5/0x290 kernel/cgroup/cgroup.c:1677
 #3: ffffffff8d1c83b0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2453 [inline]
 #3: ffffffff8d1c83b0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x19c/0x650 kernel/cgroup/cgroup.c:2959
 #4: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2455 [inline]
 #4: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x1b1/0x650 kernel/cgroup/cgroup.c:2959
 #5: ffffffff8d35ffa8 (cpuset_mutex){+.+.}-{3:3}, at: cpuset_attach+0xd9/0x560 kernel/cgroup/cpuset.c:2647
 #6: ffff888074bd9f58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 #6: ffff888074bd9f58 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0xe4/0x390 mm/mempolicy.c:386
3 locks held by syz-executor/4370:
 #0: ffff88807408a460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x269/0xbc0 fs/read_write.c:580
 #1: ffff8880599d0888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x4f0 fs/kernfs/file.c:325
 #2: ffffffff8d3535e8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:442 [inline]
 #2: ffffffff8d3535e8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xe5/0x290 kernel/cgroup/cgroup.c:1677
1 lock held by syz.4.208/4377:
 #0: ffff888074bdea58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 #0: ffff888074bdea58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x29a/0x9f0 mm/mmap.c:3235
1 lock held by sed/4534:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.114-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 46 Comm: kworker/u4:3 Not tainted 6.1.114-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: phy7 ieee80211_iface_work
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3719 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3738 [inline]
RIP: 0010:validate_chain+0x199/0x5950 kernel/locking/lockdep.c:3793
Code: 89 df e8 ca be 76 00 48 89 5c 24 28 48 8b 1b 48 85 db 74 48 48 83 c3 f8 74 42 4c 8d 7b 18 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 <74> 08 4c 89 ff e8 9d be 76 00 49 8b 07 4c 39 f0 0f 84 dc 03 00 00
RSP: 0018:ffffc90000b77480 EFLAGS: 00000046
RAX: 1ffffffff225d57b RBX: ffffffff912eabc0 RCX: ffffffff816b55e2
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff91230260
RBP: ffffc90000b77730 R08: dffffc0000000000 R09: fffffbfff224604d
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff88801f6bc6d0 R14: 672d6e35cf6529e1 R15: ffffffff912eabd8
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564bb026a030 CR3: 000000007e076000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
 __debug_check_no_obj_freed lib/debugobjects.c:968 [inline]
 debug_check_no_obj_freed+0xd8/0x4e0 lib/debugobjects.c:1009
 slab_free_hook mm/slub.c:1699 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 __kmem_cache_free+0x205/0x3c0 mm/slub.c:3674
 skb_free_head net/core/skbuff.c:762 [inline]
 skb_release_data+0x5de/0x7a0 net/core/skbuff.c:791
 skb_release_all net/core/skbuff.c:856 [inline]
 __kfree_skb net/core/skbuff.c:870 [inline]
 kfree_skb_reason+0x16f/0x390 net/core/skbuff.c:893
 kfree_skb include/linux/skbuff.h:1220 [inline]
 ieee80211_iface_work+0x260/0xce0 net/mac80211/iface.c:1724
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/22 16:23 linux-6.1.y 7ec6f9fa3d97 a93682b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in cgroup_can_fork
* Struck through repros no longer work on HEAD.