INFO: task syz.0.430:7708 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.430 state:D stack:27784 pid:7708 ppid:5790 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:788 bdev_open_by_dev+0x77/0x100 block/bdev.c:842 setup_bdev_super+0x59/0x660 fs/super.c:1496 get_tree_bdev+0x337/0x510 fs/super.c:1588 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3377 do_mount fs/namespace.c:3717 [inline] __do_sys_mount fs/namespace.c:3926 [inline] __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3903 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: 0033:0x7f232d98eec9 RSP: 002b:00007f232e75f038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f232dbe6090 RCX: 00007f232d98eec9 RDX: 0000200000000080 RSI: 0000200000000040 RDI: 0000200000000900 RBP: 00007f232da11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000001408009 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f232dbe6128 R14: 00007f232dbe6090 R15: 00007fffc25c0e28 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 2 locks held by kworker/u4:8/3473: 2 locks held by klogd/5148: #0: ffff8880b8e3c218 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:566 #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline] #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694 2 locks held by getty/5552: #0: ffff8880204280a0 (&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/5801: #0: ffff88814139b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788 1 lock held by syz.0.430/7708: #0: ffff88814139b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788 ============================================= 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 08/18/2025 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: 3503 Comm: kworker/u4:10 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:switch_mm_irqs_off+0x432/0xb10 arch/x86/mm/tlb.c:565 Code: b7 e0 b8 03 00 48 8b 04 24 48 8d 88 18 06 00 00 48 89 ca 48 c1 ea 03 48 b8 00 00 00 00 00 fc ff df 48 89 54 24 18 80 3c 02 00 <48> 89 4c 24 08 74 0f 48 8b 7c 24 08 e8 2d cd a0 00 48 8b 4c 24 08 RSP: 0018:ffffc9000c9d7600 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff88807b7e0000 RCX: ffff88807b7e8f98 RDX: 1ffff1100f6fd1f3 RSI: 0000000000000000 RDI: ffff888025bd1e00 RBP: ffffc9000c9d76d0 R08: ffff88802e34336f R09: 1ffff11005c6866d R10: dffffc0000000000 R11: ffffed1005c6866e R12: 0000000000000000 R13: ffff88802e341e01 R14: 0000000000001e59 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000015000 CR3: 000000002e29f000 CR4: 00000000003506e0 Call Trace: context_switch kernel/sched/core.c:5364 [inline] __schedule+0xf22/0x44d0 kernel/sched/core.c:6699 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:692 RIP: 0010:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00 RSP: 0018:ffffc9000c9d7a40 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0dfae592cbc88000 RDX: 0000000000000000 RSI: ffffffff8aaace60 RDI: ffffffff8afc63c0 RBP: ffffc9000c9d7b48 R08: dffffc0000000000 R09: 1ffffffff21b4ea0 R10: dffffc0000000000 R11: fffffbfff21b4ea1 R12: 1ffff9200193af54 R13: ffffffff8cd2ff20 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719 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