syzbot


INFO: task hung in do_syscall_64 (2)

Status: auto-obsoleted due to no activity on 2024/11/03 05:27
Subsystems: kernel
[Documentation on labels]
First crash: 295d, last: 285d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in do_syscall_64 input 1 419d 419d 0/28 auto-obsoleted due to no activity on 2024/06/21 21:23
linux-4.14 INFO: task hung in do_syscall_64 2 1599d 1642d 0/1 auto-closed as invalid on 2021/04/28 21:23
upstream INFO: task hung in do_syscall_64 (3) usb syz error 5 47d 145d 0/28 upstream: reported syz repro on 2024/12/22 20:16
linux-6.1 INFO: task hung in do_syscall_64 1 168d 168d 0/3 auto-obsoleted due to no activity on 2025/03/09 20:24

Sample crash report:
INFO: task udevd:9588 blocked for more than 157 seconds.
      Not tainted 6.11.0-rc1-syzkaller-00334-ga5dbd76a8942 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D
 stack:27232 pid:9588  tgid:9588  ppid:4671   flags:0x00000002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0xe37/0x5490 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6621
 schedule_hrtimeout_range_clock+0x3c7/0x430 kernel/time/hrtimer.c:2275
 ep_poll fs/eventpoll.c:2062 [inline]
 do_epoll_wait+0x13d4/0x1ae0 fs/eventpoll.c:2464
 __do_sys_epoll_wait fs/eventpoll.c:2476 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2471 [inline]
 __x64_sys_epoll_wait+0x194/0x290 fs/eventpoll.c:2471
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7c38f92457
RSP: 002b:00007ffec2bb2798 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7c38f92457
RDX: 0000000000000004 RSI: 00007ffec2bb27d8 RDI: 0000000000000004
RBP: 0000556ea9010830 R08: 0000000000000001 R09: 96132b5a1377392b
R10: 00000000ffffffff R11: 0000000000000246 R12: 0000556ea90172c0
R13: 00007ffec2bb27d8 R14: 00000000ffffffff R15: 0000556ea8fdb2c0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8ddb5ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #0: ffffffff8ddb5ca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8ddb5ca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6620
2 locks held by getty/4970:
 #0: ffff88802b5710a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900031232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2211
3 locks held by kworker/1:3/5272:
5 locks held by kworker/0:9/6672:
 #0: ffff8880196e6948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206
 #1: ffffc90003dffd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207
 #2: ffff888023855190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline]
 #2: ffff888023855190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4e20 drivers/usb/core/hub.c:5849
 #3: ffff888023888518 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3206 [inline]
 #3: ffff888023888518 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5418 [inline]
 #3: ffff888023888518 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 #3: ffff888023888518 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5821 [inline]
 #3: ffff888023888518 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x2802/0x4e20 drivers/usb/core/hub.c:5903
 #4: ffff888023059568 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5419 [inline]
 #4: ffff888023059568 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 #4: ffff888023059568 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5821 [inline]
 #4: ffff888023059568 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x282b/0x4e20 drivers/usb/core/hub.c:5903
1 lock held by syz-executor/7037:
 #0: ffffffff8ddc1438 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:328
2 locks held by dhcpcd/10497:
 #0: ffff88804a7d2258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
 #0: ffff88804a7d2258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3266
 #1: ffffffff8ddc1438 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:328
1 lock held by dhcpcd/10498:
 #0: ffff8880657ba258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
 #0: ffff8880657ba258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3266
1 lock held by dhcpcd/10499:
 #0: ffff8880657bc258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
 #0: ffff8880657bc258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3266
1 lock held by dhcpcd/10500:
 #0: ffff88807ca40258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
 #0: ffff88807ca40258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3266

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc1-syzkaller-00334-ga5dbd76a8942 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xf4e/0x1280 kernel/hung_task.c:379
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 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+0x1a/0x20 drivers/acpi/processor_idle.c:111

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/05 05:19 upstream a5dbd76a8942 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in do_syscall_64
2024/07/25 16:26 upstream c33ffdb70cc6 32fcf98f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in do_syscall_64
* Struck through repros no longer work on HEAD.