INFO: task udevd:3561 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:25520 pid: 3561 ppid: 1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2e6/0x320 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] cgroup_css_set_fork kernel/cgroup/cgroup.c:6225 [inline] cgroup_can_fork+0xc94/0xda0 kernel/cgroup/cgroup.c:6343 copy_process+0x22b5/0x3e20 kernel/fork.c:2382 kernel_clone+0x23f/0x990 kernel/fork.c:2679 __do_sys_clone kernel/fork.c:2796 [inline] __se_sys_clone kernel/fork.c:2780 [inline] __x64_sys_clone+0x19a/0x210 kernel/fork.c:2780 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: 0033:0x7f22c663f636 RSP: 002b:00007ffced772810 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffced772818 RCX: 00007f22c663f636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 000055fad9cef910 R08: 0000000000000000 R09: 000055fad9cf78e0 R10: 00007f22c6507b50 R11: 0000000000000246 R12: 00007ffced772bd0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 INFO: task udevd:4854 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:26512 pid: 4854 ppid: 3561 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2e6/0x320 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+0x25e/0x20c0 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: 0033:0x7f22c663f6c5 RSP: 002b:00007ffced772938 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000055fad9d17a40 RCX: 00007f22c663f6c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000055fad9cef910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffced772980 R14: 0000000000000000 R15: 0000000000000000 INFO: task udevd:4865 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:26992 pid: 4865 ppid: 3561 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2e6/0x320 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+0x25e/0x20c0 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: 0033:0x7f22c663f6c5 RSP: 002b:00007ffced772938 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000055fad9d11f30 RCX: 00007f22c663f6c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000055fad9cef910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffced772980 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor:4931 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:21840 pid: 4931 ppid: 4930 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662 __cgroup_procs_write+0x73/0x350 kernel/cgroup/cgroup.c:5012 cgroup_procs_write+0x23/0x40 kernel/cgroup/cgroup.c:5052 cgroup_file_write+0x2c3/0x660 kernel/cgroup/cgroup.c:3966 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x745/0xd60 fs/read_write.c:594 ksys_write+0x152/0x260 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: 0033:0x7fa53d2967ce RSP: 002b:00007ffc05499018 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055559213a500 RCX: 00007fa53d2967ce RDX: 0000000000000001 RSI: 00007ffc054990a0 RDI: 0000000000000003 RBP: 00007ffc05499610 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffc054990a0 R14: 00007ffc054995d0 R15: 00007ffc05499610 INFO: task syz-executor:4934 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:21808 pid: 4934 ppid: 4929 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662 __cgroup_procs_write+0x73/0x350 kernel/cgroup/cgroup.c:5012 cgroup_procs_write+0x23/0x40 kernel/cgroup/cgroup.c:5052 cgroup_file_write+0x2c3/0x660 kernel/cgroup/cgroup.c:3966 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x745/0xd60 fs/read_write.c:594 ksys_write+0x152/0x260 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: 0033:0x7efd3ef7d7ce RSP: 002b:00007ffea845fc88 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000555582b7f500 RCX: 00007efd3ef7d7ce RDX: 0000000000000001 RSI: 00007ffea845fd10 RDI: 0000000000000003 RBP: 00007ffea8460280 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffea845fd10 R14: 00007ffea8460240 R15: 00007ffea8460280 INFO: task syz-executor:4938 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:21840 pid: 4938 ppid: 4933 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 rwsem_down_write_slowpath+0xc87/0x1260 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+0x336/0x620 kernel/cgroup/cpuset.c:2376 cgroup_migrate_execute+0x7eb/0x1010 kernel/cgroup/cgroup.c:2597 cgroup_attach_task+0x53e/0x7b0 kernel/cgroup/cgroup.c:2892 __cgroup1_procs_write+0x2ee/0x3f0 kernel/cgroup/cgroup-v1.c:527 cgroup_file_write+0x2c3/0x660 kernel/cgroup/cgroup.c:3966 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x745/0xd60 fs/read_write.c:594 ksys_write+0x152/0x260 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: 0033:0x7f2120cdb7ce RSP: 002b:00007ffc4df63b38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000555567b39500 RCX: 00007f2120cdb7ce RDX: 0000000000000001 RSI: 00007ffc4df63bc0 RDI: 0000000000000003 RBP: 00007ffc4df64130 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffc4df63bc0 R14: 00007ffc4df640f0 R15: 00007ffc4df64130 INFO: task syz-executor:4942 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:20560 pid: 4942 ppid: 4937 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662 __cgroup_procs_write+0x73/0x350 kernel/cgroup/cgroup.c:5012 cgroup_procs_write+0x23/0x40 kernel/cgroup/cgroup.c:5052 cgroup_file_write+0x2c3/0x660 kernel/cgroup/cgroup.c:3966 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x745/0xd60 fs/read_write.c:594 ksys_write+0x152/0x260 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: 0033:0x7f61e02ef7ce RSP: 002b:00007ffddc548be8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055556523d500 RCX: 00007f61e02ef7ce RDX: 0000000000000001 RSI: 00007ffddc548c70 RDI: 0000000000000003 RBP: 00007ffddc5491e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffddc548c70 R14: 00007ffddc5491a0 R15: 00007ffddc5491e0 INFO: task udevd:4992 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:26640 pid: 4992 ppid: 3561 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 percpu_rwsem_wait+0x2e6/0x320 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+0x25e/0x20c0 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: 0033:0x7f22c663f6c5 RSP: 002b:00007ffced772938 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000055fad9d13f80 RCX: 00007f22c663f6c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000055fad9cef910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffced772980 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 1 lock held by klogd/3550: #0: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 1 lock held by udevd/3561: #0: ffffffff8c344530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x22b5/0x3e20 kernel/fork.c:2382 2 locks held by getty/3951: #0: ffff88814c6b8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 1 lock held by udevd/4854: #0: ffffffff8c344530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:830 1 lock held by udevd/4865: #0: ffffffff8c344530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:830 3 locks held by syz-executor/4931: #0: ffff88807524a460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590 #1: ffff888077173488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #2: ffffffff8c344348 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662 3 locks held by syz-executor/4934: #0: ffff88807524a460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590 #1: ffff888020d45488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #2: ffffffff8c344348 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662 1 lock held by syz-executor/4936: #0: ffffffff8c344530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:830 7 locks held by syz-executor/4938: #0: ffff888077080460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590 #1: ffff88802558f488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #2: ffffffff8c344348 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662 #3: ffffffff8c1bd1d0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2411 [inline] #3: ffffffff8c1bd1d0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x196/0x5c0 kernel/cgroup/cgroup.c:2921 #4: ffffffff8c344530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2413 [inline] #4: ffffffff8c344530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x1ac/0x5c0 kernel/cgroup/cgroup.c:2921 #5: ffffffff8c351e88 (cpuset_mutex){+.+.}-{3:3}, at: cpuset_attach+0xad/0x620 kernel/cgroup/cpuset.c:2348 #6: ffff88807ad0e328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #6: ffff88807ad0e328 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0x33/0x2c0 mm/mempolicy.c:381 3 locks held by syz-executor/4942: #0: ffff88807524a460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590 #1: ffff88807a989488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #2: ffffffff8c344348 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662 2 locks held by syz-executor/4943: #0: ffffffff8c3a8b90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline] #0: ffffffff8c3a8b90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline] #0: ffffffff8c3a8b90 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x22c/0x13f0 kernel/fork.c:1518 #1: ffff88807ad0b928 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff88807ad0b928 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline] #1: ffff88807ad0b928 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline] #1: ffff88807ad0b928 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x249/0x13f0 kernel/fork.c:1518 1 lock held by udevd/4992: #0: ffffffff8c344530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:830 2 locks held by dhcpcd-run-hook/5148: #0: ffffffff8c3a8b90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline] #0: ffffffff8c3a8b90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline] #0: ffffffff8c3a8b90 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x22c/0x13f0 kernel/fork.c:1518 #1: ffff888016c6d528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff888016c6d528 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline] #1: ffff888016c6d528 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline] #1: ffff888016c6d528 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x249/0x13f0 kernel/fork.c:1518 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:__lock_acquire+0x1db/0x7d10 kernel/locking/lockdep.c:-1 Code: c7 c0 80 af 2d 96 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 3a 65 00 00 83 3d a1 a8 d0 14 00 75 0a 41 83 fc 30 0f 83 11 58 00 00 <4c> 89 6c 24 30 44 8b 6d 20 48 c7 c0 80 bf b5 8f 49 29 c7 49 c1 ff RSP: 0018:ffffc90000ce7700 EFLAGS: 00000083 RAX: 0000000000000004 RBX: ffff8880572e9808 RCX: ffffffff962daf03 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880572e9808 RBP: ffffc90000ce7950 R08: dffffc0000000000 R09: 0000000000000001 R10: dffffc0000000000 R11: fffffbfff1b13c6e R12: 0000000000000003 R13: ffff88813fe90000 R14: ffff88813fe90ae8 R15: ffffffff8fbc0180 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f691b486000 CR3: 000000002382d000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 skb_dequeue+0x29/0x150 net/core/skbuff.c:3285 ieee80211_iface_work+0x7a7/0xc60 net/mac80211/iface.c:1507 cfg80211_wiphy_work+0x221/0x260 net/wireless/core.c:433 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287