INFO: task udevd:4301 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23296 pid: 4301 ppid: 3560 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2d8/0x310 kernel/locking/percpu-rwsem.c:160 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline] exit_signals+0x3e5/0x510 kernel/signal.c:2991 do_exit+0x256/0x20a0 kernel/exit.c:830 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe0476996c5 RSP: 002b:00007ffce2f36ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00005628167497a0 RCX: 00007fe0476996c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000056281672c910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffce2f36bf0 R14: 0000000000000000 R15: 0000000000000000 INFO: task udevd:4322 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24224 pid: 4322 ppid: 3560 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2d8/0x310 kernel/locking/percpu-rwsem.c:160 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline] exit_signals+0x3e5/0x510 kernel/signal.c:2991 do_exit+0x256/0x20a0 kernel/exit.c:830 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe0476996c5 RSP: 002b:00007ffce2f36ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000562816750f80 RCX: 00007fe0476996c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000056281672c910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffce2f36bf0 R14: 0000000000000000 R15: 0000000000000000 INFO: task udevd:4327 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24224 pid: 4327 ppid: 3560 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2d8/0x310 kernel/locking/percpu-rwsem.c:160 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline] exit_signals+0x3e5/0x510 kernel/signal.c:2991 do_exit+0x256/0x20a0 kernel/exit.c:830 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe0476996c5 RSP: 002b:00007ffce2f36ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000562816762f30 RCX: 00007fe0476996c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000056281672c910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffce2f36bf0 R14: 0000000000000000 R15: 0000000000000000 INFO: task udevd:4330 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25920 pid: 4330 ppid: 3560 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2d8/0x310 kernel/locking/percpu-rwsem.c:160 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline] exit_signals+0x3e5/0x510 kernel/signal.c:2991 do_exit+0x256/0x20a0 kernel/exit.c:830 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe0476996c5 RSP: 002b:00007ffce2f36ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00005628167686f0 RCX: 00007fe0476996c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000056281672c910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffce2f36bf0 R14: 0000000000000000 R15: 0000000000000000 INFO: task udevd:4339 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25664 pid: 4339 ppid: 3560 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2d8/0x310 kernel/locking/percpu-rwsem.c:160 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline] exit_signals+0x3e5/0x510 kernel/signal.c:2991 do_exit+0x256/0x20a0 kernel/exit.c:830 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe0476996c5 RSP: 002b:00007ffce2f36ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000056281676e740 RCX: 00007fe0476996c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000056281672c910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffce2f36bf0 R14: 0000000000000000 R15: 0000000000000000 INFO: task udevd:4340 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24768 pid: 4340 ppid: 3560 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2d8/0x310 kernel/locking/percpu-rwsem.c:160 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline] exit_signals+0x3e5/0x510 kernel/signal.c:2991 do_exit+0x256/0x20a0 kernel/exit.c:830 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe0476996c5 RSP: 002b:00007ffce2f36ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000056281676d8c0 RCX: 00007fe0476996c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000056281672c910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffce2f36bf0 R14: 0000000000000000 R15: 0000000000000000 INFO: task udevd:4341 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:26400 pid: 4341 ppid: 3560 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2d8/0x310 kernel/locking/percpu-rwsem.c:160 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline] exit_signals+0x3e5/0x510 kernel/signal.c:2991 do_exit+0x256/0x20a0 kernel/exit.c:830 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe0476996c5 RSP: 002b:00007ffce2f36ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000056281676dd00 RCX: 00007fe0476996c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000056281672c910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffce2f36bf0 R14: 0000000000000000 R15: 0000000000000000 INFO: task udevd:4348 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25056 pid: 4348 ppid: 3560 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2d8/0x310 kernel/locking/percpu-rwsem.c:160 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline] exit_signals+0x3e5/0x510 kernel/signal.c:2991 do_exit+0x256/0x20a0 kernel/exit.c:830 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe0476996c5 RSP: 002b:00007ffce2f36ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000562816752c30 RCX: 00007fe0476996c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000056281672c910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffce2f36bf0 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor:9146 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:26656 pid: 9146 ppid: 4175 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2d8/0x310 kernel/locking/percpu-rwsem.c:160 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline] exit_signals+0x3e5/0x510 kernel/signal.c:2991 do_exit+0x256/0x20a0 kernel/exit.c:830 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff6e1b58fd3 RSP: 002b:00007ffde19b02c8 EFLAGS: 00000202 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 00000000000023bb RCX: 00007ff6e1b58fd3 RDX: 0000000040000000 RSI: 00007ffde19b02dc RDI: 00000000ffffffff RBP: 00007ffde19b02dc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 INFO: task syz-executor:9866 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:19872 pid: 9866 ppid: 9856 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 rwsem_down_write_slowpath+0xc46/0x11f0 kernel/locking/rwsem.c:1165 mmap_write_lock include/linux/mmap_lock.h:71 [inline] mpol_rebind_mm+0x33/0x2c0 mm/mempolicy.c:381 cpuset_attach+0x330/0x5f0 kernel/cgroup/cpuset.c:2376 cgroup_migrate_execute+0x7eb/0x1010 kernel/cgroup/cgroup.c:2597 cgroup_attach_task+0x562/0x7e0 kernel/cgroup/cgroup.c:2892 __cgroup1_procs_write+0x2e5/0x3f0 kernel/cgroup/cgroup-v1.c:527 cgroup_file_write+0x2f7/0x630 kernel/cgroup/cgroup.c:3966 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fcea7d4997f RSP: 002b:00007ffd21453d00 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fcea7d4997f RDX: 0000000000000001 RSI: 00007ffd21453d50 RDI: 0000000000000003 RBP: 00007ffd214542c0 R08: 0000000000000000 R09: 00007ffd21453b57 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffd21453d50 R14: 00007ffd21454280 R15: 00007ffd214542c0 Showing all locks held in the system: 1 lock held by kworker/dying/9: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/21: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/23: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by khungtaskd/27: #0: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 1 lock held by kworker/dying/140: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/146: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/154: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/1341: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 2 locks held by getty/3950: #0: ffff88814ca42098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 2 locks held by syz-executor/4186: #0: ffffffff8c1a67f0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline] #0: ffffffff8c1a67f0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline] #0: ffffffff8c1a67f0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x21f/0x1380 kernel/fork.c:1518 #1: ffff88807a612b28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff88807a612b28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline] #1: ffff88807a612b28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline] #1: ffff88807a612b28 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x238/0x1380 kernel/fork.c:1518 1 lock held by kworker/dying/4195: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4197: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4204: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4254: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4270: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4281: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by udevd/4301: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4313: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by udevd/4322: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by udevd/4327: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by udevd/4330: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by udevd/4339: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by udevd/4340: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by udevd/4341: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by udevd/4348: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4352: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4393: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4409: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4415: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4417: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4423: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4426: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/4911: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5369: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5655: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5656: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5657: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5659: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5662: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5663: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5664: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5665: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5667: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5669: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5670: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5671: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5672: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5673: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5675: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5676: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5677: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5679: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5682: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5683: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5685: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5688: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5694: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/5695: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by kworker/dying/6660: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 2 locks held by syz-executor/9073: #0: ffffffff8c1a67f0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline] #0: ffffffff8c1a67f0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline] #0: ffffffff8c1a67f0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x21f/0x1380 kernel/fork.c:1518 #1: ffff88807a613928 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff88807a613928 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline] #1: ffff88807a613928 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline] #1: ffff88807a613928 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x238/0x1380 kernel/fork.c:1518 1 lock held by syz-executor/9146: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 7 locks held by syz-executor/9866: #0: ffff88801f0dc460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590 #1: ffff88807c071c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #2: ffffffff8c141f08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662 #3: ffffffff8bfbadd0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2411 [inline] #3: ffffffff8bfbadd0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x17c/0x580 kernel/cgroup/cgroup.c:2921 #4: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2413 [inline] #4: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x192/0x580 kernel/cgroup/cgroup.c:2921 #5: ffffffff8c14fa48 (cpuset_mutex){+.+.}-{3:3}, at: cpuset_attach+0xac/0x5f0 kernel/cgroup/cpuset.c:2348 #6: ffff88801e64d528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #6: ffff88801e64d528 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0x33/0x2c0 mm/mempolicy.c:381 1 lock held by syz.7.1691/9925: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by syz.9.1710/9972: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729