INFO: task syz.0.17:5092 blocked for more than 143 seconds. Not tainted 5.15.186-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:25864 pid: 5092 ppid: 4818 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x97/0x280 kernel/time/timer.c:1890 do_wait_for_common+0x29a/0x440 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x48/0x60 kernel/sched/completion.c:138 kthread_stop+0x16e/0x540 kernel/kthread.c:666 ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:263 ext4_fill_super+0x6608/0x9a00 fs/ext4/super.c:5086 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3014 do_mount fs/namespace.c:3357 [inline] __do_sys_mount fs/namespace.c:3565 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3542 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fbe3fd9c90a RSP: 002b:00007fbe3f00be68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fbe3f00bef0 RCX: 00007fbe3fd9c90a RDX: 0000400000000040 RSI: 0000400000000000 RDI: 00007fbe3f00beb0 RBP: 0000400000000040 R08: 00007fbe3f00bef0 R09: 0000000003010008 R10: 0000000003010008 R11: 0000000000000246 R12: 0000400000000000 R13: 00007fbe3f00beb0 R14: 0000000000000538 R15: 0000400000000340 Showing all locks held in the system: 3 locks held by kworker/1:1/23: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90000ddfd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff88805a920240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x271/0x3240 drivers/net/netdevsim/fib.c:1480 1 lock held by khungtaskd/27: #0: ffffffff8c11bfa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3935: #0: ffff88802bd6f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026462e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 1 lock held by syz.0.17/5092: #0: ffff88807b1020e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.1.24/5135: #0: ffff888075b940e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.2.25/5157: #0: ffff88807e86c0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.3.26/5181: #0: ffff88805dce80e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.4.38/5248: #0: ffff888059e520e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.5.42/5285: #0: ffff8880232220e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.6.48/5328: #0: ffff888029e800e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.7.54/5377: #0: ffff88807cf140e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.8.56/5408: #0: ffff888027ab20e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.9.67/5465: #0: ffff8880567960e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.186-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5089 Comm: kworker/u4:6 Not tainted 5.15.186-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_preemption_disabled+0x60/0x110 lib/smp_processor_id.c:19 Code: 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 <74> cc 65 4c 8b 3d e6 c1 60 76 41 f6 47 2f 04 74 0a 41 83 bf 10 04 RSP: 0018:ffffc900033bfa88 EFLAGS: 00000046 RAX: 0000000000000000 RBX: d76267b928a0e515 RCX: 0000000080000000 RDX: 0000000000000002 RSI: ffffffff8a0b2460 RDI: ffffffff8a59a900 RBP: ffffc900033bfbd0 R08: dffffc0000000000 R09: fffffbfff1ad1586 R10: fffffbfff1ad1586 R11: 1ffffffff1ad1585 R12: ffff88801dd546c0 R13: dffffc0000000000 R14: ffff88801dd54660 R15: 1ffff92000677f64 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f754b88e000 CR3: 000000002a30b000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline] lock_release+0x540/0x870 kernel/locking/lockdep.c:5645 rcu_read_unlock include/linux/rcupdate.h:772 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline] batadv_nc_worker+0x25b/0x5c0 net/batman-adv/network-coding.c:723 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287