INFO: task syz.0.1027:9763 blocked for more than 143 seconds. Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1027 state:D stack:25984 pid:9763 tgid:9762 ppid:5828 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913 __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+0xdee/0x1960 fs/open.c:955 vfs_open+0x3b/0x370 fs/open.c:1085 do_open fs/namei.c:3828 [inline] path_openat+0x2c74/0x3580 fs/namei.c:3987 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1427 do_sys_open fs/open.c:1442 [inline] __do_sys_openat fs/open.c:1458 [inline] __se_sys_openat fs/open.c:1453 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1453 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: 0033:0x7f733838b710 RSP: 002b:00007f73391b4b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f733838b710 RDX: 0000000000000000 RSI: 00007f73391b4c10 RDI: 00000000ffffff9c RBP: 00007f73391b4c10 R08: 0000000000000000 R09: 002364626e2f7665 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f73385a5fa0 R15: 00007ffcd05ae918 Showing all locks held in the system: 2 locks held by ksoftirqd/1/24: #0: ffff8880b863e918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:606 #1: ffff8880b8728948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41d/0x7a0 kernel/sched/psi.c:987 1 lock held by khungtaskd/30: #0: ffffffff8e939ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e939ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e939ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by getty/5584: #0: ffff888030d390a0 (&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+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by udevd/6640: #0: ffff888143f944c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903 3 locks held by kworker/u8:12/6646: #0: ffff88801ac81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc9001d25fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9001d25fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 #2: ffffffff8fcc3b08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:285 1 lock held by syz.0.1027/9763: #0: ffff888143f944c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903 2 locks held by syz.3.1429/11183: #0: ffffffff8fcc3b08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:702 [inline] #0: ffffffff8fcc3b08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3521 #1: ffffffff8e93f3b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:302 [inline] #1: ffffffff8e93f3b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:996 1 lock held by syz.5.1430/11191: #0: ffff8880b863e918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:606 1 lock held by syz.5.1430/11193: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 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+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/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: 11197 Comm: syz.1.1431 Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:check_preemption_disabled+0x4/0x120 lib/smp_processor_id.c:13 Code: 8c 48 c7 c6 40 3c 60 8c eb 1c 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 <41> 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 RSP: 0018:ffffc900049378a8 EFLAGS: 00000283 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff819ad504 RDX: 0000000000000000 RSI: ffffffff8c603c40 RDI: ffffffff8c603c00 RBP: ffffc90004937a38 R08: ffffffff901b8e77 R09: 1ffffffff20371ce R10: dffffc0000000000 R11: fffffbfff20371cf R12: 1ffff92000926f24 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff1100656e82b FS: 00007fc6e8b9b6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f436c379178 CR3: 00000000496a6000 CR4: 0000000000350ef0 Call Trace: rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:716 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xe3/0x550 kernel/locking/lockdep.c:5822 __might_fault+0xc6/0x120 mm/memory.c:6840 do_recvmmsg+0x59c/0xab0 net/socket.c:2931 __sys_recvmmsg net/socket.c:2999 [inline] __do_sys_recvmmsg net/socket.c:3022 [inline] __se_sys_recvmmsg net/socket.c:3015 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3015 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: 0033:0x7fc6e7d8cda9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc6e8b9b038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fc6e7fa6080 RCX: 00007fc6e7d8cda9 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000004 RBP: 00007fc6e7e0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc6e7fa6080 R15: 00007fffaef35438