syzbot


INFO: task hung in coredump_task_exit

Status: auto-obsoleted due to no activity on 2023/07/26 12:35
Reported-by: syzbot+75066b239a5b1d172735@syzkaller.appspotmail.com
First crash: 616d, last: 616d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in coredump_task_exit (2) 3 211d 286d 0/3 auto-obsoleted due to no activity on 2024/08/13 23:40
upstream INFO: task hung in coredump_task_exit (2) kernel 9 151d 338d 0/28 auto-obsoleted due to no activity on 2024/10/03 07:15
upstream INFO: task hung in coredump_task_exit kernel 12 444d 769d 0/28 auto-obsoleted due to no activity on 2023/12/15 00:03

Sample crash report:
INFO: task syz-executor.3:22982 blocked for more than 143 seconds.
      Not tainted 6.1.21-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:0     pid:22982 ppid:4363   flags:0x0000000d
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5238 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6551
 schedule+0xc4/0x170 kernel/sched/core.c:6627
 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:2858
 do_signal arch/arm64/kernel/signal.c:1076 [inline]
 do_notify_resume+0x3ac/0x3470 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:581
INFO: task syz-executor.3:22989 blocked for more than 143 seconds.
      Not tainted 6.1.21-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:0     pid:22989 ppid:4363   flags:0x00000009
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5238 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6551
 schedule+0xc4/0x170 kernel/sched/core.c:6627
 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:2858
 do_signal arch/arm64/kernel/signal.c:1076 [inline]
 do_notify_resume+0x3ac/0x3470 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:581

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffff800015754a30 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:510
1 lock held by rcu_tasks_trace/13:
 #0: ffff800015755230 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:510
1 lock held by khungtaskd/28:
 #0: ffff800015754860 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:305
1 lock held by udevd/3839:
2 locks held by getty/3988:
 #0: ffff0000d4087098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80001ca002f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1210 drivers/tty/n_tty.c:2177
3 locks held by syz-executor.5/4346:
2 locks held by kworker/u4:9/8982:
4 locks held by kworker/u4:16/9277:
 #0: ffff0000c0e3d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2262
 #1: ffff800020dc7c20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2264
 #2: ffff000121af40e0 (&type->s_umount_key#66){++++}-{3:3}, at: trylock_super+0x28/0xf8 fs/super.c:415
 #3: ffff000120601140 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2207 [inline]
 #3: ffff000120601140 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x40c/0x60c fs/f2fs/segment.c:418
2 locks held by syz-executor.3/22981:
1 lock held by udevd/23026:
2 locks held by syz-executor.3/24740:
1 lock held by syz-executor.4/24745:
1 lock held by syz-executor.0/24743:
4 locks held by syz-executor.2/24748:

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


Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/03/28 12:35 linux-6.1.y e3a87a10f259 47f3aaf1 .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.