syzbot


INFO: task hung in sock_def_readable

Status: auto-obsoleted due to no activity on 2025/05/03 05:25
Subsystems: net
[Documentation on labels]
First crash: 201d, last: 201d

Sample crash report:
INFO: task udevd:5339 blocked for more than 143 seconds.
      Not tainted 6.13.0-syzkaller-09760-g69e858e0b8b2 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:R  running task     stack:24496 pid:5339  tgid:5339  ppid:5207   task_flags:0x400140 flags:0x00000002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5377 [inline]
 __schedule+0x190e/0x4c90 kernel/sched/core.c:6764
 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6943
 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6967
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0x130/0x140 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock+0x18c/0x1e0 kernel/sched/wait.c:108
 sock_def_readable+0x20f/0x5a0 net/core/sock.c:3476
 unix_dgram_sendmsg+0xf23/0x1df0 net/unix/af_unix.c:2163
 sock_sendmsg_nosec net/socket.c:713 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:728
 sock_write_iter+0x2d7/0x3f0 net/socket.c:1132
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0xacf/0xd10 fs/read_write.c:679
 ksys_write+0x18f/0x2b0 fs/read_write.c:731
 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: 0033:0x7fcfb1716bf2
RSP: 002b:00007ffc1e58b7d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcfb1716bf2
RDX: 0000000000000000 RSI: 00007ffc1e58b82f RDI: 000000000000000a
RBP: 00007ffc1e58b82f R08: 0000000000000001 R09: 0000000000000000
R10: 000000000000010f R11: 0000000000000246 R12: 000000000000000a
R13: 00007fcfb1ad6ae0 R14: 0000000000000000 R15: 000056512b734910
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/12:
1 lock held by khungtaskd/30:
 #0: ffffffff8e9387a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e9387a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e9387a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
3 locks held by kworker/1:1/57:
2 locks held by getty/5587:
 #0: ffff8880357920a0 (&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
7 locks held by kworker/0:4/5892:
 #0: ffff888144a8bd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff888144a8bd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
 #1: ffffc9000435fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc9000435fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317
 #2: ffff888144be0190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
 #2: ffff888144be0190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5851
 #3: ffff88805dc62190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
 #3: ffff88805dc62190 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x103/0x950 drivers/usb/core/hub.c:2296
 #4: ffff88806c0e4160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
 #4: ffff88806c0e4160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
 #4: ffff88806c0e4160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293
 #5: ffffffff8f75a288 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:201 [inline]
 #5: ffffffff8f75a288 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x2f3/0x620 drivers/input/input.c:2221
 #6: ffffffff8e93dc78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline]
 #6: ffffffff8e93dc78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:996
3 locks held by kworker/u9:1/21267:
 #0: ffff888027ce4948 ((wq_completion)hci7){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff888027ce4948 ((wq_completion)hci7){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
 #1: ffffc90019287c60 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc90019287c60 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317
 #2: ffff888036474d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_open net/bluetooth/hci_core.c:409 [inline]
 #2: ffff888036474d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_power_on+0x1bf/0x6b0 net/bluetooth/hci_core.c:940
1 lock held by syz.4.3330/27529:
3 locks held by kworker/1:4/30843:
4 locks held by udevd/5339:
 #0: ffff8880342df9e0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb4/0xd70 fs/seq_file.c:182
 #1: ffff888066e78c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154
 #2: ffff888062314a58 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155
 #3: ffff88805dc62190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
 #3: ffff88805dc62190 (&dev->mutex){....}-{4:4}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2729
2 locks held by syz-executor/5546:
 #0: ffff888046784d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:480 [inline]
 #0: ffff888046784d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2677
 #1: ffff888046784078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x5c8/0x11c0 net/bluetooth/hci_sync.c:5185
1 lock held by syz-executor/5821:
2 locks held by syz-executor/6516:
2 locks held by syz-executor/6533:
1 lock held by syz.5.5097/7060:
1 lock held by syz-executor/7108:
4 locks held by syz-executor/7116:
1 lock held by syz-executor/7129:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-syzkaller-09760-g69e858e0b8b2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/02 05:16 upstream 69e858e0b8b2 0dff8567 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in sock_def_readable
* Struck through repros no longer work on HEAD.