syzbot


INFO: task hung in exit_signals

Status: upstream: reported on 2024/10/14 22:06
Reported-by: syzbot+f4992587d50b0a2342b2@syzkaller.appspotmail.com
First crash: 53d, last: 44d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in exit_signals cgroups 3 91d 106d 0/28 auto-obsoleted due to no activity on 2024/12/06 15:04
linux-4.14 INFO: task hung in exit_signals 1 1847d 1847d 0/1 auto-closed as invalid on 2020/03/16 09:13

Sample crash report:
INFO: task udevd:3628 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:25832 pid:3628  ppid:3093   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: 0033:0x7f22c06fca90
RSP: 002b:00007ffdc0c6bca8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f22c06fca90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000007 R09: f3d09e1b70a0b64f
R10: 00000000ffffffff R11: 0000000000000206 R12: 0000562758de0ae0
R13: 00007ffdc0c6bce8 R14: 0000000000000001 R15: 0000562758dd6910
 </TASK>
INFO: task udevd:3630 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:26184 pid:3630  ppid:3093   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: 0033:0x7f22c06fca90
RSP: 002b:00007ffdc0c6bca8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f22c06fca90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000007 R09: f3d09e1b70a0b64f
R10: 00000000ffffffff R11: 0000000000000206 R12: 0000562758ded310
R13: 00007ffdc0c6bce8 R14: 0000000000000001 R15: 0000562758dd6910
 </TASK>
INFO: task udevd:3655 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:3655  ppid:3093   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: 0033:0x7f22c06fca90
RSP: 002b:00007ffdc0c6bca8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f22c06fca90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000007 R09: f3d09e1b70a0b64f
R10: 00000000ffffffff R11: 0000000000000202 R12: 0000562758df9490
R13: 00007ffdc0c6bce8 R14: 0000000000000001 R15: 0000562758dd6910
 </TASK>
INFO: task udevd:3750 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:3750  ppid:3093   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: 0033:0x7f22c06fca90
RSP: 002b:00007ffdc0c6bca8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f22c06fca90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000007 R09: f3d09e1b70a0b64f
R10: 00000000ffffffff R11: 0000000000000206 R12: 0000562758df4960
R13: 00007ffdc0c6bce8 R14: 0000000000000001 R15: 0000562758dd6910
 </TASK>
INFO: task udevd:3751 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:3751  ppid:3093   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: 0033:0x7f22c06fca90
RSP: 002b:00007ffdc0c6bca8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f22c06fca90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000007 R09: f3d09e1b70a0b64f
R10: 00000000ffffffff R11: 0000000000000206 R12: 0000562758e04fa0
R13: 00007ffdc0c6bce8 R14: 0000000000000001 R15: 0000562758dd6910
 </TASK>
INFO: task syz-executor:3859 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:3859  ppid:3625   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: 0033:0x7f9b13f74213
RSP: 002b:00007ffe35485b38 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 0000000000000f2c RCX: 00007f9b13f74213
RDX: 0000000040000000 RSI: 00007ffe35485b4c RDI: 00000000ffffffff
RBP: 00007ffe35485b4c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000c
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:5065 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:20352 pid:5065  ppid:5032   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: 0033:0x7f5bb8d7cadf
RSP: 002b:00007ffe81b029f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f5bb8d7cadf
RDX: 0000000000000001 RSI: 00007ffe81b02a40 RDI: 0000000000000003
RBP: 00007ffe81b02fa0 R08: 0000000000000000 R09: 00007ffe81b02847
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007ffe81b02a40 R14: 00007ffe81b02f60 R15: 00007ffe81b02fa0
 </TASK>
INFO: task syz.3.445:5192 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.3.445       state:D stack:24032 pid:5192  ppid:3884   flags:0x00004006
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]
 exit_mmap+0x29a/0x9f0 mm/mmap.c:3235
 __mmput+0x115/0x3c0 kernel/fork.c:1199
 exit_mm+0x226/0x300 kernel/exit.c:565
 do_exit+0x9f6/0x26a0 kernel/exit.c:858
 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: 0033:0x7f9b13f7dff9
RSP: 002b:00007f9b14ca6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: fffffffffffffffc RBX: 00007f9b14135f80 RCX: 00007f9b13f7dff9
RDX: 0000000000000050 RSI: 0000000020000500 RDI: 000000000000000a
RBP: 00007f9b13ff0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9b14135f80 R15: 00007ffe354855e8
 </TASK>

Showing all locks held in the system:
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/27:
 #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/3082:
 #0: ffff8880b8e3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
1 lock held by dhcpcd/3307:
 #0: ffff88801d7c3d58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff88801d7c3d58 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0x21d/0x370 mm/mmap.c:2914
2 locks held by getty/3396:
 #0: ffff88802e4a1098 (&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/3628:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
1 lock held by udevd/3630:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
2 locks held by syz-executor/3638:
 #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: ffff88807b0bf958 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff88807b0bf958 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:593 [inline]
 #1: ffff88807b0bf958 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1540 [inline]
 #1: ffff88807b0bf958 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x3e5/0x1990 kernel/fork.c:1589
1 lock held by udevd/3655:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
1 lock held by udevd/3750:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
1 lock held by udevd/3751:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
2 locks held by syz-executor/3854:
 #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: ffff88807d3826d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff88807d3826d8 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:593 [inline]
 #1: ffff88807d3826d8 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1540 [inline]
 #1: ffff88807d3826d8 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x3e5/0x1990 kernel/fork.c:1589
2 locks held by syz-executor/3857:
 #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: ffff88801ab40158 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff88801ab40158 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:593 [inline]
 #1: ffff88801ab40158 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1540 [inline]
 #1: ffff88801ab40158 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x3e5/0x1990 kernel/fork.c:1589
1 lock held by syz-executor/3859:
 #0: ffffffff8d3537d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x69f/0x26a0 kernel/exit.c:827
7 locks held by syz-executor/5065:
 #0: ffff88802ba6c460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x269/0xbc0 fs/read_write.c:580
 #1: ffff888027890888 (&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: ffff8880779b0158 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 #6: ffff8880779b0158 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0xe4/0x390 mm/mempolicy.c:386
1 lock held by syz.3.445/5192:
 #0: ffff88807dbf88d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 #0: ffff88807dbf88d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x29a/0x9f0 mm/mmap.c:3235
3 locks held by dhcpcd/5212:
 #0: ffff88807e5df148 (&sig->cred_guard_mutex){+.+.}-{3:3}, at: prepare_bprm_creds fs/exec.c:1482 [inline]
 #0: ffff88807e5df148 (&sig->cred_guard_mutex){+.+.}-{3:3}, at: bprm_execve+0xc0/0x18a0 fs/exec.c:1822
 #1: ffff88807e5df1e0 (&sig->exec_update_lock){++++}-{3:3}, at: exec_mmap+0xf5/0x5b0 fs/exec.c:999
 #2: ffff88801d7c3d58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock_killable include/linux/mmap_lock.h:126 [inline]
 #2: ffff88801d7c3d58 (&mm->mmap_lock){++++}-{3:3}, at: exec_mmap+0x17f/0x5b0 fs/exec.c:1009

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 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: 3703 Comm: kworker/u4:6 Not tainted 6.1.114-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: phy15 ieee80211_iface_work
RIP: 0010:check_preemption_disabled+0x4f/0x110 lib/smp_processor_id.c:55
Code: 5b 75 a9 ff ff ff 7f 74 22 65 48 8b 04 25 28 00 00 00 48 3b 44 24 08 0f 85 c7 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5e 41 5f <c3> 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 74 c9
RSP: 0018:ffffc900041af6d0 EFLAGS: 00000082
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000080000000
RDX: ffff88802cd98000 RSI: ffffffff8b0c0fa0 RDI: ffffffff8b5d7540
RBP: 00000000ffffffff R08: ffffffff8a1e93fb R09: ffffffff843959a1
R10: 000000000000000c R11: ffff88802cd98000 R12: 0000000000000246
R13: ffff88802cd98000 R14: 00000000ffffffff R15: ffffffff8d32b000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562758de3030 CR3: 000000000d08e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline]
 lock_is_held_type+0x76/0x180 kernel/locking/lockdep.c:5704
 rht_ptr_rcu include/linux/rhashtable.h:369 [inline]
 __rhashtable_lookup include/linux/rhashtable.h:599 [inline]
 rhltable_lookup+0x324/0x7f0 include/linux/rhashtable.h:688
 sta_info_hash_lookup net/mac80211/sta_info.c:195 [inline]
 sta_info_get+0x124/0x2a0 net/mac80211/sta_info.c:207
 ieee80211_update_sta_info net/mac80211/ibss.c:1000 [inline]
 ieee80211_rx_bss_info net/mac80211/ibss.c:1118 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1609 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x10f0/0x2dd0 net/mac80211/ibss.c:1638
 ieee80211_iface_process_skb net/mac80211/iface.c:1668 [inline]
 ieee80211_iface_work+0x7aa/0xce0 net/mac80211/iface.c:1722
 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 (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/24 10:33 linux-6.1.y 7ec6f9fa3d97 0d144d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in exit_signals
2024/10/14 22:06 linux-6.1.y aa4cd140bba5 b01b6661 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in exit_signals
* Struck through repros no longer work on HEAD.