INFO: task kthreadd:2 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kthreadd state:D stack:27336 pid: 2 ppid: 0 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 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] cgroup_css_set_fork kernel/cgroup/cgroup.c:6225 [inline] cgroup_can_fork+0xc94/0xda0 kernel/cgroup/cgroup.c:6343 copy_process+0x2290/0x3e00 kernel/fork.c:2382 kernel_clone+0x219/0x930 kernel/fork.c:2679 kernel_thread+0xc8/0x120 kernel/fork.c:2731 create_kthread kernel/kthread.c:357 [inline] kthreadd+0x520/0x6f0 kernel/kthread.c:703 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: task kworker/u4:3:156 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:22824 pid: 156 ppid: 2 flags:0x00004000 Workqueue: netns cleanup_net 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 schedule_timeout+0x97/0x280 kernel/time/timer.c:1890 do_wait_for_common+0x29a/0x440 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x48/0x60 kernel/sched/completion.c:138 kthread_stop+0x16e/0x540 kernel/kthread.c:666 __netif_napi_del+0x685/0x7a0 net/core/dev.c:7055 netif_napi_del include/linux/netdevice.h:2547 [inline] peer_remove_after_dead+0xe1/0x1a0 drivers/net/wireguard/peer.c:125 wg_peer_remove_all+0x447/0x4e0 drivers/net/wireguard/peer.c:184 wg_destruct+0x176/0x300 drivers/net/wireguard/device.c:238 netdev_run_todo+0x82d/0xa40 net/core/dev.c:10691 default_device_exit_batch+0x33b/0x390 net/core/dev.c:11668 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x77b/0xb80 net/core/net_namespace.c:635 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: task udevd:4231 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:27200 pid: 4231 ppid: 3561 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: 0033:0x7f4e931ab6c5 RSP: 002b:00007ffc3a91de38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000055c339e91840 RCX: 00007f4e931ab6c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000055c339e70910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc3a91de80 R14: 0000000000000000 R15: 0000000000000000 INFO: task udevd:4251 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:27648 pid: 4251 ppid: 3561 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: 0033:0x7f4e931ab6c5 RSP: 002b:00007ffc3a91de38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000055c339e94f80 RCX: 00007f4e931ab6c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000055c339e70910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc3a91de80 R14: 0000000000000000 R15: 0000000000000000 INFO: task udevd:4252 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:27104 pid: 4252 ppid: 3561 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: 0033:0x7f4e931ab6c5 RSP: 002b:00007ffc3a91de38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000055c339e934d0 RCX: 00007f4e931ab6c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000055c339e70910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc3a91de80 R14: 0000000000000000 R15: 0000000000000000 INFO: task napi/wg0-0:4289 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:napi/wg0-0 state:D stack:28896 pid: 4289 ppid: 2 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 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 kthread_exit+0x11/0x20 kernel/kthread.c:283 kthread+0x454/0x520 kernel/kthread.c:336 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: task syz-executor:4312 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:21472 pid: 4312 ppid: 4304 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 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xc71/0x2390 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+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: 0033:0x7f8cdc82d97f RSP: 002b:00007ffd3745a5a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f8cdc82d97f RDX: 0000000000000001 RSI: 00007ffd3745a5f0 RDI: 0000000000000003 RBP: 00007ffd3745ab60 R08: 0000000000000000 R09: 00007ffd3745a3f7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffd3745a5f0 R14: 00007ffd3745ab20 R15: 00007ffd3745ab60 INFO: task syz-executor:4328 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:21688 pid: 4328 ppid: 4308 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: 0033:0x7f122bbd297f RSP: 002b:00007ffe41dbac30 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f122bbd297f RDX: 0000000000000001 RSI: 00007ffe41dbac80 RDI: 0000000000000003 RBP: 00007ffe41dbb1f0 R08: 0000000000000000 R09: 00007ffe41dbaa87 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffe41dbac80 R14: 00007ffe41dbb1b0 R15: 00007ffe41dbb1f0 INFO: task syz-executor:4329 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:21664 pid: 4329 ppid: 4311 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 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xc71/0x2390 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+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: 0033:0x7f5eae91397f RSP: 002b:00007ffdf4957140 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f5eae91397f RDX: 0000000000000001 RSI: 00007ffdf4957190 RDI: 0000000000000003 RBP: 00007ffdf4957700 R08: 0000000000000000 R09: 00007ffdf4956f97 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffdf4957190 R14: 00007ffdf49576c0 R15: 00007ffdf4957700 Showing all locks held in the system: 1 lock held by kthreadd/2: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x2290/0x3e00 kernel/fork.c:2382 1 lock held by khungtaskd/27: #0: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:3/156: #0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90001cb7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d22c690 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:589 #3: ffff8880231813e8 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_destruct+0x112/0x300 drivers/net/wireguard/device.c:233 1 lock held by dhcpcd/3854: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x2290/0x3e00 kernel/fork.c:2382 2 locks held by getty/3950: #0: ffff88814cc79098 (&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 1 lock held by udevd/4226: #0: ffff8880759c2b28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff8880759c2b28 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0xf3/0x230 mm/mmap.c:2949 1 lock held by udevd/4231: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by udevd/4251: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by udevd/4252: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by napi/wg0-0/4289: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 1 lock held by syz-executor/4310: #0: ffffffff8c1420f0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x256/0x20a0 kernel/exit.c:830 3 locks held by syz-executor/4312: #0: ffff8880792d2460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590 #1: ffff88801f627488 (&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 2 locks held by syz-executor/4318: #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: ffff88802bd8ce28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff88802bd8ce28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline] #1: ffff88802bd8ce28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline] #1: ffff88802bd8ce28 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x238/0x1380 kernel/fork.c:1518 7 locks held by syz-executor/4328: #0: ffff8880191b0460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590 #1: ffff88805e27b088 (&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: ffff888024ca7128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #6: ffff888024ca7128 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0x33/0x2c0 mm/mempolicy.c:381 3 locks held by syz-executor/4329: #0: ffff8880792d2460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590 #1: ffff888078ecd888 (&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 2 locks held by syz-executor/4330: #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: ffff888024ca6328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff888024ca6328 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline] #1: ffff888024ca6328 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline] #1: ffff888024ca6328 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x238/0x1380 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 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 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 08/18/2025 Workqueue: 0x0 (bat_events) RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x80 kernel/kcov.c:294 Code: 28 4d 39 ca 77 22 89 ff 89 f6 4a c7 44 02 08 03 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 <48> 8b 04 24 65 48 8b 0d 04 a2 8a 7e 65 8b 15 05 a2 8a 7e 81 e2 00 RSP: 0018:ffffc90000ce7b08 EFLAGS: 00000046 RAX: ffffffff817de836 RBX: 0000000000000001 RCX: ffff88813fed0000 RDX: 0000000040000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 1ffff11017227613 R08: dffffc0000000000 R09: ffffed1017227469 R10: ffffed1017227469 R11: 1ffff11017227468 R12: 1ffff110172275c1 R13: dffffc0000000000 R14: ffff8880b913ae08 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3a5e386000 CR3: 000000007dd1a000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_on+0x16/0x80 kernel/trace/trace_preemptirq.c:42 raw_spin_rq_unlock_irq kernel/sched/sched.h:1338 [inline] finish_lock_switch+0x12f/0x280 kernel/sched/core.c:4803 finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921 context_switch kernel/sched/core.c:5052 [inline] __schedule+0x11c3/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 worker_thread+0xf5c/0x12a0 kernel/workqueue.c:2478 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287