INFO: task syz.2.558:7487 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.558 state:D stack:26632 pid:7487 ppid:5766 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747 blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 swsusp_check+0x5b/0x390 kernel/power/swap.c:1525 software_resume+0x4d/0x2e0 kernel/power/hibernate.c:958 resume_store+0x2f2/0x450 kernel/power/hibernate.c:1216 kernfs_fop_write_iter+0x3b6/0x520 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x43b/0x940 fs/read_write.c:584 ksys_write+0x147/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa68178f749 RSP: 002b:00007fa682543038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fa6819e6180 RCX: 00007fa68178f749 RDX: 0000000000000012 RSI: 0000200000000000 RDI: 0000000000000008 RBP: 00007fa681813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa6819e6218 R14: 00007fa6819e6180 R15: 00007ffc6c870dc8 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 3 locks held by kworker/u4:2/34: 2 locks held by kworker/u4:4/78: #0: ffff888140a99938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888140a99938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900015e7d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900015e7d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 2 locks held by getty/5530: #0: ffff8880316820a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000327e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by udevd/5774: #0: ffff88814134a4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 6 locks held by syz.2.558/7487: #0: ffff88805e5c4ac8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040 #1: ffff888031ae0418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580 #2: ffff8880255c4088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343 #3: ffff888141e4f6d0 (kn->active#69){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #3: ffff888141e4f6d0 (kn->active#69){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x23a/0x520 fs/kernfs/file.c:344 #4: ffffffff8cbe3988 (system_transition_mutex){+.+.}-{3:3}, at: software_resume+0x43/0x2e0 kernel/power/hibernate.c:957 #5: ffff88814134a4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 2 locks held by syz.3.1017/8841: #0: ffffffff8d4c2e28 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x59/0x3a0 drivers/char/misc.c:125 #1: ffffffff8cbe3988 (system_transition_mutex){+.+.}-{3:3}, at: lock_system_sleep+0x49/0x70 kernel/power/main.c:56 1 lock held by syz.4.1025/8858: #0: ffffffff8d4c2e28 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x59/0x3a0 drivers/char/misc.c:125 1 lock held by syz.1.1033/8878: #0: ffffffff8d4c2e28 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x59/0x3a0 drivers/char/misc.c:125 1 lock held by syz.1.1033/8879: #0: ffffffff8d4c2e28 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x59/0x3a0 drivers/char/misc.c:125 1 lock held by syz.1.1033/8880: #0: ffffffff8d4c2e28 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x59/0x3a0 drivers/char/misc.c:125 1 lock held by syz.0.1037/8890: #0: ffffffff8d4c2e28 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x59/0x3a0 drivers/char/misc.c:125 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 34 Comm: kworker/u4:2 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:check_kcov_mode kernel/kcov.c:193 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x60 kernel/kcov.c:216 Code: f0 24 7e 7e 65 8b 15 f1 24 7e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc RSP: 0018:ffffc90000aafa78 EFLAGS: 00000246 RAX: ffffffff886acc18 RBX: 0000000000c00000 RCX: ffff88801ca60000 RDX: 0000000000000000 RSI: ffffffff8dfb7960 RDI: 000000000000002e RBP: 000000000000002e R08: ffff88801ca60000 R09: 0000000000000003 R10: 000000000000002e R11: 0000000000000000 R12: 0000000000000005 R13: ffffffff8b489cc3 R14: ffffffff8b489cc2 R15: 000000000000002e FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c37cfd8 CR3: 00000000765c9000 CR4: 00000000003506f0 Call Trace: in_aton+0x2c8/0x430 net/core/utils.c:61 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:763 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x4a3/0xb00 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 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