INFO: task syz.3.2903:16255 blocked for more than 143 seconds.
      Not tainted syzkaller #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.2903      state:D stack:22336 pid:16255 tgid:16252 ppid:5831   task_flags:0x40054c flags:0x00080001
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185
 __down_write_common kernel/locking/rwsem.c:1317 [inline]
 __down_write kernel/locking/rwsem.c:1326 [inline]
 down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591
 mmap_write_lock include/linux/mmap_lock.h:335 [inline]
 exit_mmap+0x27b/0xb10 mm/mmap.c:1285
 __mmput+0x118/0x430 kernel/fork.c:1173
 exit_mm+0x1da/0x2c0 kernel/exit.c:581
 do_exit+0x658/0x2310 kernel/exit.c:959
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f079db8f749
RSP: 002b:00007f079e9a5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: 0000000000000034 RBX: 00007f079dde6090 RCX: 00007f079db8f749
RDX: 0000000000008000 RSI: 0000200000000080 RDI: 0000000000000004
RBP: 00007f079dc13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f079dde6128 R14: 00007f079dde6090 R15: 00007ffe517e3e08
 </TASK>
INFO: task syz.4.2923:16324 blocked for more than 143 seconds.
      Not tainted syzkaller #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2923      state:D stack:26712 pid:16324 tgid:16317 ppid:5832   task_flags:0x40054c flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185
 __down_write_common kernel/locking/rwsem.c:1317 [inline]
 __down_write kernel/locking/rwsem.c:1326 [inline]
 down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591
 mmap_write_lock include/linux/mmap_lock.h:335 [inline]
 exit_mmap+0x27b/0xb10 mm/mmap.c:1285
 __mmput+0x118/0x430 kernel/fork.c:1173
 exit_mm+0x1da/0x2c0 kernel/exit.c:581
 do_exit+0x658/0x2310 kernel/exit.c:959
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0fd7d8f749
RSP: 002b:00007f0fd8c84038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: fffffffffffffff2 RBX: 00007f0fd7fe6090 RCX: 00007f0fd7d8f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000b
RBP: 00007f0fd7e13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0fd7fe6128 R14: 00007f0fd7fe6090 R15: 00007fff6f297c38
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
 #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc90000117b80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc90000117b80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
1 lock held by khungtaskd/31:
 #0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:2/36:
 #0: ffff88801aa9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88801aa9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc90000ac7b80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc90000ac7b80 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0 net/core/net_namespace.c:670
 #3: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
 #3: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:248
 #4: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #4: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956
2 locks held by getty/5592:
 #0: ffff88814e0760a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5830:
 #0: ffff88802f050340 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline]
 #0: ffff88802f050340 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285
1 lock held by syz-executor/5834:
 #0: ffff888079d62800 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline]
 #0: ffff888079d62800 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285
3 locks held by kworker/0:14/7468:
 #0: ffff88813ff15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88813ff15948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc9001bbefb80 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc9001bbefb80 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by syz-executor/16198:
 #0: ffff888079d63440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline]
 #0: ffff888079d63440 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285
1 lock held by syz.3.2903/16255:
 #0: ffff88805725b440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline]
 #0: ffff88805725b440 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285
1 lock held by syz.4.2923/16324:
 #0: ffff888078d81bc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline]
 #0: ffff888078d81bc0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285
1 lock held by udevd/16398:
 #0: ffff888141758358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
5 locks held by kworker/u8:6/16529:
4 locks held by kworker/u8:20/17080:
 #0: ffff8880b873a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
 #1: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
 #2: ffff8880b87260d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1004 [inline]
 #2: ffff8880b87260d8 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1085
 #3: ffffffff99b8ae98 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x87/0x540 lib/debugobjects.c:818

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xf95/0xfe0 kernel/hung_task.c:515
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 1170 Comm: kworker/u8:11 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:32 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:lock_release+0xa1/0x3b0 kernel/locking/lockdep.c:5885
Code: 92 41 83 bf 2c 0b 00 00 00 0f 85 18 02 00 00 49 81 3e c0 63 42 93 0f 84 0b 02 00 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 <48> 8b 5c 24 20 fa 48 c7 c7 80 71 7a 8d e8 0d 38 bd 09 65 ff 05 36
RSP: 0018:ffffc9000426ee10 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffffff90238801 RCX: 54209d742a5da500
RDX: ffffc9000426ef01 RSI: ffffffff8bc08340 RDI: ffffffff8bc08300
RBP: dffffc0000000000 R08: ffffc9000426f268 R09: 0000000000000000
R10: ffffc9000426ef98 R11: fffff5200084ddf5 R12: ffffc9000426f278
R13: ffffffff81743f85 R14: ffffffff8df41a20 R15: ffff888026e3bd00
FS:  0000000000000000(0000) GS:ffff888125f35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fefa71c6e9c CR3: 000000000dd3a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:897 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0x1ab1/0x23d0 arch/x86/kernel/unwind_orc.c:695
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf5/0x1f0 mm/page_owner.c:165
 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
 prep_new_page mm/page_alloc.c:1854 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab+0x86/0x3b0 mm/slub.c:3248
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xf2b/0x1960 mm/slub.c:4656
 __slab_alloc+0x65/0x100 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 __do_kmalloc_node mm/slub.c:5656 [inline]
 __kmalloc_node_track_caller_noprof+0x5d4/0x820 mm/slub.c:5764
 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:608
 __alloc_skb+0x27e/0x430 net/core/skbuff.c:690
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:818 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:875 [inline]
 nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:921
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>