syzbot


INFO: task hung in coredump_task_exit (2)

Status: upstream: reported on 2024/02/21 14:31
Reported-by: syzbot+508684b94dabb81b8dbe@syzkaller.appspotmail.com
First crash: 115d, last: 40d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in coredump_task_exit kernel 12 273d 598d 0/27 auto-obsoleted due to no activity on 2023/12/15 00:03
linux-6.1 INFO: task hung in coredump_task_exit 1 445d 445d 0/3 auto-obsoleted due to no activity on 2023/07/26 12:35

Sample crash report:
INFO: task syz-executor.1:4878 blocked for more than 143 seconds.
      Not tainted 6.1.90-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1  state:D stack:0     pid:4878  ppid:4252   flags:0x0000000d
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6558
 schedule+0xc4/0x170 kernel/sched/core.c:6634
 coredump_task_exit+0x278/0x394 kernel/exit.c:432
 do_exit+0x1b8/0x1a88 kernel/exit.c:819
 do_group_exit+0x194/0x22c kernel/exit.c:1019
 get_signal+0x14a0/0x158c kernel/signal.c:2862
 do_signal arch/arm64/kernel/signal.c:1076 [inline]
 do_notify_resume+0x3ac/0x3474 arch/arm64/kernel/signal.c:1129
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
 el0_svc+0x9c/0x168 arch/arm64/kernel/entry-common.c:638
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
INFO: task syz-executor.1:4961 blocked for more than 143 seconds.
      Not tainted 6.1.90-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1  state:D stack:0     pid:4961  ppid:4252   flags:0x0000000d
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6558
 schedule+0xc4/0x170 kernel/sched/core.c:6634
 schedule_timeout+0xb8/0x344 kernel/time/timer.c:1941
 do_wait_for_common+0x30c/0x468 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion_state+0x50/0x7c kernel/sched/completion.c:254
 coredump_wait fs/coredump.c:405 [inline]
 do_coredump+0x7f4/0x2234 fs/coredump.c:562
 get_signal+0xfd8/0x158c kernel/signal.c:2848
 do_signal arch/arm64/kernel/signal.c:1076 [inline]
 do_notify_resume+0x3ac/0x3474 arch/arm64/kernel/signal.c:1129
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
 el0_svc+0x9c/0x168 arch/arm64/kernel/entry-common.c:638
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffff800015a14e70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffff800015a15670 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
 #0: 
ffff800015a14ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349
4 locks held by kworker/u4:5/1746:
 #0: ffff0000c0845138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
 #1: ffff8000226d7c20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
 #2: ffff800017e14fd0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf4/0x994 net/core/net_namespace.c:563
 #3: ffff800015a1a140 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x58/0x5c4 kernel/rcu/tree.c:4018
2 locks held by getty/3982:
 #0: ffff0000d609f098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80001bcf02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1214 drivers/tty/n_tty.c:2188
3 locks held by kworker/1:8/4442:
 #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
 #1: ffff80001e6a7c20 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
 #2: ffff0000dde72240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x270/0x32bc drivers/net/netdevsim/fib.c:1489
3 locks held by kworker/1:12/4607:
 #0: ffff0000d5cc4d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
 #1: 
ffff80001f777c20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
 #2: ffff800017e20e08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
3 locks held by kworker/1:15/4610:
 #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
 #1: ffff80001e547c20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
 #2: ffff800017e20e08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
3 locks held by kworker/u4:8/6470:
1 lock held by syz-executor.2/8165:
1 lock held by syz-executor.4/8366:
 #0: ffff0000f2fd20e0 (&type->s_umount_key#54/1){+.+.}-{3:3}, at: alloc_super+0x1b4/0x824 fs/super.c:228
1 lock held by syz-executor.3/8405:
 #0: ffff800017e20e08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffff800017e20e08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e8/0xd94 net/core/rtnetlink.c:6118
1 lock held by rm/8409:

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


Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/05 23:39 linux-6.1.y 909ba1f1b414 610f2a54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in coredump_task_exit
2024/04/03 12:47 linux-6.1.y e5cd595e23c1 7925100d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in coredump_task_exit
2024/02/21 14:30 linux-6.1.y 8b4118fabd6e 3af7dd65 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in coredump_task_exit
* Struck through repros no longer work on HEAD.