syzbot


INFO: task hung in do_syscall_64

Status: upstream: reported on 2024/11/29 20:24
Reported-by: syzbot+bb38f5eb3cc8ca1eeba3@syzkaller.appspotmail.com
First crash: 22d, last: 22d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in do_syscall_64 input 1 273d 273d 0/28 auto-obsoleted due to no activity on 2024/06/21 21:23
upstream INFO: task hung in do_syscall_64 (2) kernel 2 138d 149d 0/28 auto-obsoleted due to no activity on 2024/11/03 05:27
linux-4.14 INFO: task hung in do_syscall_64 2 1453d 1495d 0/1 auto-closed as invalid on 2021/04/28 21:23

Sample crash report:
INFO: task dhcpcd:3918 blocked for more than 160 seconds.
      Not tainted 6.1.119-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:S stack:20648 pid:3918  ppid:3917   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 do_wait+0x797/0xb80 kernel/exit.c:1633
 kernel_wait4+0x29e/0x3e0 kernel/exit.c:1777
 __do_sys_wait4 kernel/exit.c:1805 [inline]
 __se_sys_wait4 kernel/exit.c:1801 [inline]
 __x64_sys_wait4+0x130/0x1e0 kernel/exit.c:1801
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd7ecaeaba9
RSP: 002b:00007fff497e2f28 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00007fff497e2f88 RCX: 00007fd7ecaeaba9
RDX: 00007fd7ecadce12 RSI: 0000000000000058 RDI: 00007fff497e2f88
RBP: 00007fd7ecadce12 R08: 00007fff497e2fe0 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000206 R12: 00007fff497e2fe0
R13: ffffffffffffff80 R14: 0000000000000000 R15: 00007fff497e2fe0
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/7:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc900000c7d20 (fqdir_free_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8d330400 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x5f0 kernel/rcu/tree.c:4019
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32b110 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d32b910 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
2 locks held by kworker/0:1/14:
1 lock held by khungtaskd/28:
 #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510
2 locks held by kworker/u4:2/41:
2 locks held by kworker/u4:3/46:
2 locks held by kworker/u4:5/1080:
2 locks held by kworker/0:3/1181:
2 locks held by getty/4006:
 #0: ffff8880312c6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198
2 locks held by kworker/1:3/4306:
7 locks held by kworker/1:6/4315:
2 locks held by kworker/u4:11/4385:
6 locks held by kworker/u4:17/4590:
 #0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90005017d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e4fe3d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:566
 #3: ffffffff8e50a768 (rtnl_mutex){+.+.}-{3:3}, at: caif_exit_net+0x6a/0x4f0 net/caif/caif_dev.c:527
 #4: ffff8880568c6480 (&caifn->caifdevs.lock){+.+.}-{3:3}, at: caif_exit_net+0x7d/0x4f0 net/caif/caif_dev.c:528
 #5: ffffffff8d330538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #5: ffffffff8d330538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962
3 locks held by kworker/0:7/5310:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90004037d20 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e50a768 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104
2 locks held by kworker/0:2/8585:
3 locks held by kworker/1:1/8755:
 #0: ffff88814c918d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90003c97d20 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e50a768 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x15/0x30 net/ipv6/addrconf.c:4656
2 locks held by kworker/1:11/9661:
2 locks held by kworker/0:5/9866:
 #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/29 20:23 linux-6.1.y e4d90d63d385 5df23865 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in do_syscall_64
* Struck through repros no longer work on HEAD.