INFO: task syz.2.1490:10606 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.2.1490 state:D stack:27520 pid:10606 tgid:10602 ppid:5579 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7607 rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670 __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline] rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578 sync_bdevs+0x276/0x470 block/bdev.c:1297 ksys_sync fs/sync.c:105 [inline] __ia32_sys_sync+0xc5/0x120 fs/sync.c:111 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f32fff8e0d9 RSP: 002b:00007f32fe1c5028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f3300216090 RCX: 00007f32fff8e0d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f3300216090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3300216128 R14: 00007f3300216090 R15: 00007ffd172a6448 INFO: task syz.2.1490:10609 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.2.1490 state:D stack:26968 pid:10609 tgid:10602 ppid:5579 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7607 rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670 __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline] rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578 sync_bdevs+0x276/0x470 block/bdev.c:1297 ksys_sync fs/sync.c:105 [inline] __ia32_sys_sync+0xc5/0x120 fs/sync.c:111 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f32fff8e0d9 RSP: 002b:00007f32fe1a4028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f3300216180 RCX: 00007f32fff8e0d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f3300216180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3300216218 R14: 00007f3300216180 R15: 00007ffd172a6448 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by dhcpcd/5241: #0: ffff888039bb4928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe7/0xee0 net/netlink/af_netlink.c:2273 #1: ffffffff8f5ac238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f5ac238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dump_ifinfo+0xa74/0x14b0 net/core/rtnetlink.c:2562 2 locks held by getty/5337: #0: ffff8880352a30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cb62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 6 locks held by kworker/0:4/5591: 1 lock held by udevd/5691: #0: ffff8880264304c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd00 block/bdev.c:948 3 locks held by kworker/0:5/5704: 6 locks held by kworker/u8:40/6871: #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9001cb5fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9001cb5fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f59d680 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673 #3: ffff88803a829160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #3: ffff88803a829160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff88803a829160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:557 #4: ffff88803a7e4310 (&devlink->lock_key#9){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline] #4: ffff88803a7e4310 (&devlink->lock_key#9){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff88803a7e4310 (&devlink->lock_key#9){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:557 #5: ffffffff8f5ac238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #5: ffffffff8f5ac238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2163 3 locks held by kworker/u8:45/6876: #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9001cbbfc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9001cbbfc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5ac238 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 1 lock held by syz.2.1490/10606: #0: ffff8880264304c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x276/0x470 block/bdev.c:1297 1 lock held by syz.2.1490/10609: #0: ffff8880264304c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x276/0x470 block/bdev.c:1297 9 locks held by syz-executor/12288: 2 locks held by syz-executor/12982: #0: ffffffff8ed109a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ed109a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ed109a8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f5ac238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f5ac238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f5ac238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 1 lock held by syz.4.2394/13135: 1 lock held by syz.4.2394/13138: #0: ffff88803fdce138 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff88803fdce138 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release net/socket.c:709 [inline] #0: ffff88803fdce138 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: sock_close+0x82/0x220 net/socket.c:1501 1 lock held by syz.3.2485/13424: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 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+0xfd7/0x1030 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