INFO: task syz.1.1180:9646 blocked for mo[ 529.785899][ T39] INFO: task syz.1.1180:9646 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1180 state:D stack:27672 pid:9646 tgid:9645 ppid:5607 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x169e/0x54f0 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563
rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1662
__rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1779 [inline]
rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1819
__rt_mutex_lock kernel/locking/rtmutex.c:1834 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:553
bdev_open+0xe0/0xcc0 block/bdev.c:953
blkdev_open+0x485/0x620 block/fops.c:697
do_dentry_open+0x83d/0x13e0 fs/open.c:947
vfs_open+0x3b/0x350 fs/open.c:1079
do_open fs/namei.c:4699 [inline]
path_openat+0x2e43/0x38a0 fs/namei.c:4858
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f80a0d9d60e
RSP: 002b:00007f809f02db28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f809f02e6c0 RCX: 00007f80a0d9d60e
RDX: 0000000000000002 RSI: 00007f809f02dc00 RDI: ffffffffffffff9c
RBP: 00007f809f02dc00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f80a1056038 R14: 00007f80a1055fa0 R15: 00007ffedf3cea18
Showing all locks held in the system:
1 lock held by khungtaskd/39:
#0: ffffffff8e1c81c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e1c81c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e1c81c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777
2 locks held by kworker/0:1H/58:
#0: ffff88801faacd38 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284
#1: ffffc9000124fc40 ((work_completion)(&q->timeout_work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285
2 locks held by getty/5369:
#0: ffff8880378750a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cbb2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u9:3/5615:
#0: ffff8880502e8138 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284
#1: ffffc90004837c40 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285
#2: ffff88803b450f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_open net/bluetooth/hci_core.c:429 [inline]
#2: ffff88803b450f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_power_on+0x1ac/0x710 net/bluetooth/hci_core.c:960
1 lock held by udevd/6335:
#0: ffff888027b594c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:953
1 lock held by udevd/6337:
#0: ffff888027c624c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:953
1 lock held by udevd/6411:
#0: ffff888027c014c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:953
1 lock held by udevd/6570:
#0: ffff8880279494c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:953
1 lock held by udevd/7923:
#0: ffff888027b094c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:953
1 lock held by udevd/8309:
#0: ffff8880278e14c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:953
1 lock held by udevd/8441:
#0: ffff8880279b94c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:953
1 lock held by udevd/8480:
#0: ffff8880278594c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:953
1 lock held by udevd/8788:
#0: ffff8880277a94c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:953
1 lock held by syz.1.1180/9646:
#0: ffff8880277a94c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:953
2 locks held by syz.2.1534/10808:
#0: ffff888033f000d0 (&type->s_umount_key#92/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345
#1: ffff8880278594c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:953
5 locks held by dhcpcd-run-hook/11820:
#0: ffffffff8e2994d0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1533 [inline]
#0: ffffffff8e2994d0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x130/0x4a0 kernel/fork.c:1586
#1: ffff88802dc3deb0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline]
#1: ffff88802dc3deb0 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x181/0x1d50 mm/mmap.c:1739
#2: ffff88801143b7b0 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:544 [inline]
#2: ffff88801143b7b0 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x26f/0x1d50 mm/mmap.c:1746
#3: ffffffff8e30c3d0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
#3: ffffffff8e30c3d0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:294
#4: ffff8880b8642d98 (&pcp->lock){+.+.}-{3:3}, at: __free_frozen_pages+0x7e5/0x10f0 mm/page_alloc.c:2968
2 locks held by syz.4.1783/11836:
#0: ffff88803a8e80a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline]
#0: ffff88803a8e80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:345 [inline]
#0: ffff88803a8e80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline]
#0: ffff88803a8e80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0xb8/0x520 drivers/tty/tty_ldisc.c:780
#1: ffff88803a8ef0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:295 [inline]
#1: ffff88803a8ef0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:347 [inline]
#1: ffff88803a8ef0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline]
#1: ffff88803a8ef0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0xdc/0x520 drivers/tty/tty_ldisc.c:780
1 lock held by syz.0.1785/11845:
#0: ffff88806041f450 (&sb->s_type->i_mutex_key#4/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline]
#0: ffff88806041f450 (&sb->s_type->i_mutex_key#4/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline]
#0: ffff88806041f450 (&sb->s_type->i_mutex_key#4/1){+.+.}-{4:4}, at: start_dirop+0x4f/0x90 fs/namei.c:2938
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: bb 6f 02 e9 43 c9 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 63 0b 18 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc900001e7e20 EFLAGS: 00000246
RAX: 00000000002b097d RBX: ffffffff8199b8da RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d764ff0 RDI: ffffffff8baa6fe0
RBP: ffffc900001e7f10 R08: ffff8880b8733e9b R09: 1ffff110170e67d3
R10: dffffc0000000000 R11: ffffed10170e67d4 R12: 0000000000000001
R13: 1ffff11003b59b88 R14: 0000000000000001 R15: 1ffff11003b59b88
FS: 0000000000000000(0000) GS:ffff888125dde000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8dd82c0e9c CR3: 0000000054a9c000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
arch_safe_halt arch/x86/kernel/process.c:766 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147