BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 29, name: kworker/u4:1
preempt_count: 100, expected: 0
RCU nest depth: 0, expected: 0
4 locks held by kworker/u4:1/29:
 #0: ffff0000c0134d38 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x270/0x504 kernel/workqueue.c:2262
 #1: ffff80000f66bd80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x29c/0x504 kernel/workqueue.c:2264
 #2: ffff80000d8aaf18 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x68/0x648 net/core/net_namespace.c:563
 #3: ffff800008003e20 ((&dlci->t1)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:31 [inline]
 #3: ffff800008003e20 ((&dlci->t1)){+.-.}-{0:0}, at: call_timer_fn+0x54/0x144 kernel/time/timer.c:1464
Preemption disabled at:
[<ffff800008010080>] _stext+0x80/0x37c
CPU: 0 PID: 29 Comm: kworker/u4:1 Not tainted 6.1.0-rc5-syzkaller-32269-g9500fc6e9e60 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022
Workqueue: netns cleanup_net
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156
 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 __might_resched+0x208/0x218 kernel/sched/core.c:9890
 __might_sleep+0x48/0x78 kernel/sched/core.c:9819
 __mutex_lock_common+0x6c/0xca8 kernel/locking/mutex.c:580
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 gsm_send+0x1a0/0x260 drivers/tty/n_gsm.c:724
 gsm_dlci_t1+0xa8/0x1e0
 call_timer_fn+0x90/0x144 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1519 [inline]
 __run_timers+0x280/0x374 kernel/time/timer.c:1790
 run_timer_softirq+0x34/0x5c kernel/time/timer.c:1803
 _stext+0x168/0x37c
 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79
 call_on_irq_stack+0x2c/0x54 arch/arm64/kernel/entry.S:892
 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:84
 invoke_softirq+0x70/0xbc kernel/softirq.c:452
 __irq_exit_rcu+0xf0/0x140 kernel/softirq.c:650
 irq_exit_rcu+0x10/0x40 kernel/softirq.c:662
 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline]
 el1_interrupt+0x38/0x68 arch/arm64/kernel/entry-common.c:486
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491
 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:580
 arch_local_irq_restore+0x8/0x10 arch/arm64/include/asm/irqflags.h:122
 lock_is_held include/linux/lockdep.h:283 [inline]
 __might_resched+0x34/0x218 kernel/sched/core.c:9852
 inet_twsk_purge+0x80/0x48c net/ipv4/inet_timewait_sock.c:267
 dccp_v4_exit_batch+0x20/0x2c net/dccp/ipv4.c:1055
 ops_exit_list net/core/net_namespace.c:174 [inline]
 cleanup_net+0x3cc/0x648 net/core/net_namespace.c:601
 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
 worker_thread+0x340/0x610 kernel/workqueue.c:2436
 kthread+0x12c/0x158 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863

=============================
[ BUG: Invalid wait context ]
6.1.0-rc5-syzkaller-32269-g9500fc6e9e60 #0 Tainted: G        W         
-----------------------------
kworker/u4:1/29 is trying to lock:
ffff0001152adc30 (&gsm->tx_mutex){+.+.}-{3:3}, at: gsm_send+0x1a0/0x260 drivers/tty/n_gsm.c:724
other info that might help us debug this:
context-{2:2}
4 locks held by kworker/u4:1/29:
 #0: ffff0000c0134d38 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x270/0x504 kernel/workqueue.c:2262
 #1: ffff80000f66bd80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x29c/0x504 kernel/workqueue.c:2264
 #2: ffff80000d8aaf18 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x68/0x648 net/core/net_namespace.c:563
 #3: ffff800008003e20 ((&dlci->t1)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:31 [inline]
 #3: ffff800008003e20 ((&dlci->t1)){+.-.}-{0:0}, at: call_timer_fn+0x54/0x144 kernel/time/timer.c:1464
stack backtrace:
CPU: 0 PID: 29 Comm: kworker/u4:1 Tainted: G        W          6.1.0-rc5-syzkaller-32269-g9500fc6e9e60 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022
Workqueue: netns cleanup_net
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156
 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 print_lock_invalid_wait_context kernel/locking/lockdep.c:4707 [inline]
 check_wait_context kernel/locking/lockdep.c:4768 [inline]
 __lock_acquire+0x9c8/0x3084 kernel/locking/lockdep.c:5005
 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668
 __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 gsm_send+0x1a0/0x260 drivers/tty/n_gsm.c:724
 gsm_dlci_t1+0xa8/0x1e0
 call_timer_fn+0x90/0x144 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1519 [inline]
 __run_timers+0x280/0x374 kernel/time/timer.c:1790
 run_timer_softirq+0x34/0x5c kernel/time/timer.c:1803
 _stext+0x168/0x37c
 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79
 call_on_irq_stack+0x2c/0x54 arch/arm64/kernel/entry.S:892
 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:84
 invoke_softirq+0x70/0xbc kernel/softirq.c:452
 __irq_exit_rcu+0xf0/0x140 kernel/softirq.c:650
 irq_exit_rcu+0x10/0x40 kernel/softirq.c:662
 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline]
 el1_interrupt+0x38/0x68 arch/arm64/kernel/entry-common.c:486
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491
 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:580
 arch_local_irq_restore+0x8/0x10 arch/arm64/include/asm/irqflags.h:122
 lock_is_held include/linux/lockdep.h:283 [inline]
 __might_resched+0x34/0x218 kernel/sched/core.c:9852
 inet_twsk_purge+0x80/0x48c net/ipv4/inet_timewait_sock.c:267
 dccp_v4_exit_batch+0x20/0x2c net/dccp/ipv4.c:1055
 ops_exit_list net/core/net_namespace.c:174 [inline]
 cleanup_net+0x3cc/0x648 net/core/net_namespace.c:601
 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
 worker_thread+0x340/0x610 kernel/workqueue.c:2436
 kthread+0x12c/0x158 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863