INFO: task syz.0.92:6283 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.92 state:D stack:26984 pid:6283 ppid:5757 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 blkdev_open+0x152/0x360 block/fops.c:589 do_dentry_open+0x8c6/0x1500 fs/open.c:929 do_open fs/namei.c:3640 [inline] path_openat+0x274b/0x3190 fs/namei.c:3797 do_filp_open+0x1c5/0x3d0 fs/namei.c:3824 do_sys_openat2+0x12c/0x1c0 fs/open.c:1421 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1447 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: 0033:0x7f2f5198df90 RSP: 002b:00007f2f52913b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000000a800 RCX: 00007f2f5198df90 RDX: 000000000000a800 RSI: 00007f2f52913c10 RDI: 00000000ffffff9c RBP: 00007f2f52913c10 R08: 0000000000000000 R09: 002364626e2f7665 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007f2f51be6038 R14: 00007f2f51be5fa0 R15: 00007fff12c8d528 Showing all locks held in the system: 1 lock held by khungtaskd/28: #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 2 locks held by getty/5523: #0: ffff88814c51a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by udevd/5752: #0: ffff8880218174c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 2 locks held by syz-executor/5758: #0: ffff88807b39a0e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807b39a0e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807b39a0e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 #1: ffffffff8d147928 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 3 locks held by kworker/1:3/5826: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90004affd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90004affd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff88802435e240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26c/0x3170 drivers/net/netdevsim/fib.c:1491 3 locks held by kworker/1:4/5844: #0: ffff888147267138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888147267138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90004b1fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90004b1fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff8880b8f2c2f8 (lock#6){..-.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #2: ffff8880b8f2c2f8 (lock#6){..-.}-{2:2}, at: kcov_remote_stop+0x73/0x6e0 kernel/kcov.c:1005 1 lock held by syz.0.92/6283: #0: ffff8880218174c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 2 locks held by syz-executor/6521: #0: ffff8880642e00e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880642e00e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880642e00e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 #1: ffffffff8d147928 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/6821: #0: ffff8880773ce0e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880773ce0e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880773ce0e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 #1: ffffffff8d147928 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/7424: #0: ffff8880265fc0e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880265fc0e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880265fc0e0 (&type->s_umount_key#101){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 #1: ffffffff8d147928 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 4 locks held by kworker/u4:11/7493: 1 lock held by syz.8.439/8267: #0: ffffffff8cd357c0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 41 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:__asan_memset+0x5/0x40 mm/kasan/shadow.c:83 Code: 0f 1f 44 00 00 f3 0f 1e fa 89 f6 48 8b 0c 24 ba 01 00 00 00 e9 bc ea ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 55 <41> 56 53 48 89 d3 89 f5 49 89 fe 48 8b 4c 24 18 48 89 d6 ba 01 00 RSP: 0018:ffffc90000b1f4c8 EFLAGS: 00000246 RAX: ffffc90000b1f6f0 RBX: ffffc90000b1f5e0 RCX: ffff888018ae0000 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90000b1f5f8 RBP: ffffc90000b1f5f8 R08: ffff888018ae0000 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000000 R12: ffffc90000b1f5a8 R13: dffffc0000000000 R14: ffffffff81dcd2ee R15: ffffffff8ed09aca FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc53b66fe0 CR3: 000000000cb30000 CR4: 00000000003526e0 Call Trace: unwind_next_frame+0x1648/0x2970 arch/x86/kernel/unwind_orc.c:592 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843 skb_kfree_head net/core/skbuff.c:949 [inline] skb_free_head net/core/skbuff.c:961 [inline] skb_release_data+0x634/0x800 net/core/skbuff.c:991 skb_release_all net/core/skbuff.c:1057 [inline] __kfree_skb net/core/skbuff.c:1071 [inline] consume_skb+0xb2/0x110 net/core/skbuff.c:1287 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x76f/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