INFO: task syz.5.2375:13405 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.2375      state:D stack:25384 pid:13405 ppid:9369   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 fuse_set_nowrite+0x1f7/0x340 fs/fuse/dir.c:1766
 fuse_sync_writes fs/fuse/file.c:510 [inline]
 fuse_flush+0x2d2/0x8b0 fs/fuse/file.c:534
 filp_flush fs/open.c:1534 [inline]
 filp_close+0xb1/0x150 fs/open.c:1547
 __range_close fs/file.c:698 [inline]
 __close_range+0x379/0x690 fs/file.c:755
 __do_sys_close_range fs/open.c:1600 [inline]
 __se_sys_close_range fs/open.c:1597 [inline]
 __x64_sys_close_range+0x7a/0x90 fs/open.c:1597
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4bc759e0d9
RSP: 002b:00007ffc4a3dfaf8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007ffc4a3dfbe0 RCX: 00007f4bc759e0d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000009453d R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b33a20000 R11: 0000000000000246 R12: 00007ffc4a3dfc20
R13: 00007f4bc782618c R14: 0000000000094697 R15: 00007f4bc7826180
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/1:2/790:
 #0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc900038d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc900038d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
5 locks held by kworker/u4:6/1069:
 #0: ffff88801a25d138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801a25d138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000436fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000436fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffffffff8e3ca0d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x14c/0xbb0 net/core/net_namespace.c:606
 #3: ffffffff8e3d70c8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0xcb/0x4a0 net/ipv6/ip6_gre.c:1651
 #4: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
 #4: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
2 locks held by getty/5530:
 #0: ffff888030fea0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
3 locks held by syz-executor/12573:
1 lock held by syz-executor/12582:
 #0: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
 #0: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
1 lock held by syz.5.2375/13405:
 #0: ffff88805db83e20 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #0: ffff88805db83e20 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: fuse_flush+0x2ca/0x8b0 fs/fuse/file.c:533
3 locks held by kworker/u4:4/13839:
 #0: ffff888017c71938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888017c71938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000c6e7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000c6e7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffffffff8e3d70c8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286
1 lock held by syz-executor/14536:
 #0: ffffffff8e3d70c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d70c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6481
1 lock held by syz.1.2689/14602:
 #0: ffffffff8e3d70c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d70c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6481
1 lock held by syz.1.2689/14604:
 #0: ffffffff8e3d70c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d70c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6481
1 lock held by syz.1.2689/14605:
 #0: ffffffff8e3d70c8 (rtnl_mutex){+.+.}-{3:3}, at: do_ip_setsockopt+0xd1b/0x2d50 net/ipv4/ip_sockglue.c:1046
1 lock held by syz.1.2689/14606:
 #0: ffffffff8e3d70c8 (rtnl_mutex){+.+.}-{3:3}, at: do_ip_setsockopt+0xd1b/0x2d50 net/ipv4/ip_sockglue.c:1046
1 lock held by syz.1.2689/14607:
 #0: ffffffff8e3d70c8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2fc/0x1d70 net/ipv4/devinet.c:1101
1 lock held by rm/14622:

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf59/0xfa0 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13185 Comm: kworker/u4:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0x17/0x80 kernel/kcov.c:293
Code: 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d a0 44 7c 7e 65 8b 15 a1 44 7c 7e <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 1c 16 00 00
RSP: 0018:ffffc900036575b0 EFLAGS: 00000283
RAX: ffffffff813ba891 RBX: ffffffff8e9f21bc RCX: ffff88805ef05a00
RDX: 0000000080000002 RSI: ffffffff81760e29 RDI: ffffffff81760e85
RBP: ffffffff8e9f2190 R08: ffffc90003657750 R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff81760e85
R13: ffffffff8e9f2190 R14: ffffffff81760e29 R15: ffffffff8e9f21a4
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055da20dad950 CR3: 0000000030391000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 __orc_find arch/x86/kernel/unwind_orc.c:102 [inline]
 orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
 unwind_next_frame+0x4c1/0x2990 arch/x86/kernel/unwind_orc.c:494
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc_node_track_caller+0xb4/0x230 mm/slab_common.c:1027
 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
 alloc_skb include/linux/skbuff.h:1316 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x253/0xa90 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>