INFO: task syz.1.2615:14817 blocked for more than 143 seconds. Not tainted 6.14.0-rc4-syzkaller-00073-g5394eea10651 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.2615 state:D stack:25440 pid:14817 tgid:14814 ppid:5820 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 bdev_open+0xf0/0xc50 block/bdev.c:903 blkdev_open+0x38e/0x4e0 block/fops.c:652 do_dentry_open+0xdec/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13e/0x1d0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f64d618bad0 RSP: 002b:00007f64d7051b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f64d618bad0 RDX: 0000000000000000 RSI: 00007f64d7051c10 RDI: 00000000ffffff9c RBP: 00007f64d7051c10 R08: 0000000000000000 R09: 002364626e2f7665 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f64d63a5fa0 R15: 00007ffd003141f8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by getty/5578: #0: ffff8880361c20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211 1 lock held by udevd/5822: #0: ffff888025b314c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903 1 lock held by udevd/5843: #0: ffff8880255ee4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903 1 lock held by udevd/6051: #0: ffff888025b354c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903 1 lock held by kworker/u8:23/6655: #0: ffff8880b863e7d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:606 3 locks held by kworker/0:1/11256: #0: ffff888021ab0948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888021ab0948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3317 #1: ffffc9000c077c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000c077c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3317 #2: ffff888145367190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #2: ffff888145367190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5861 1 lock held by syz.1.2615/14817: #0: ffff8880255ee4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903 1 lock held by syz.0.2849/15719: #0: ffff888025b314c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903 2 locks held by syz.6.2971/16202: #0: ffff8880777c2c08 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline] #0: ffff8880777c2c08 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff8880777c2c08 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: sock_close+0x90/0x240 net/socket.c:1398 #1: ffffffff8eb3e438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:302 [inline] #1: ffffffff8eb3e438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x820 kernel/rcu/tree_exp.h:996 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc4-syzkaller-00073-g5394eea10651 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 15418 Comm: kworker/u8:6 Not tainted 6.14.0-rc4-syzkaller-00073-g5394eea10651 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_preemption_disabled+0x60/0x120 lib/smp_processor_id.c:19 Code: 00 48 3b 44 24 08 0f 85 ce 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5e 41 5f c3 cc cc cc cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 04 24 00 02 00 00 74 c5 49 89 f6 49 89 ff 65 4c 8b 24 25 00 d5 RSP: 0018:ffffc90003d47948 EFLAGS: 00000046 RAX: 0000000080000000 RBX: 0000000000000001 RCX: ffffc90003d47a03 RDX: 0000000000000002 RSI: ffffffff8c2ab6a0 RDI: ffffffff8c801b00 RBP: ffffc90003d47aa8 R08: ffffffff903bc277 R09: 1ffffffff207784e R10: dffffc0000000000 R11: fffffbfff207784f R12: 1ffff920007a8f3c R13: 0000000000000246 R14: ffffc90003d47a10 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f25fdf78ab8 CR3: 000000000e938000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 00000000ffff000b DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:469 [inline] lock_release+0x5ec/0xa30 kernel/locking/lockdep.c:5874 rcu_lock_release include/linux/rcupdate.h:347 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x28b/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244