syzbot


INFO: task hung in nbd_ioctl

Status: upstream: reported C repro on 2023/06/26 06:58
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+df34fe61d8d75eab5996@syzkaller.appspotmail.com
First crash: 330d, last: 25d
Fix bisection: failed (error log, bisect log)
  
Bug presence (1)
Date Name Commit Repro Result
2023/06/26 upstream (ToT) 6995e2de6891 C [report] INFO: task hung in nbd_ioctl
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 INFO: task hung in nbd_ioctl C done 18 1607d 1681d 1/1 fixed on 2019/12/28 10:32
linux-4.14 INFO: task hung in nbd_ioctl (2) C done 16 1354d 1599d 1/1 fixed on 2020/10/21 11:01
upstream INFO: task hung in nbd_ioctl (2) nbd 37 1361d 1414d 15/26 fixed on 2020/09/25 01:17
upstream INFO: task hung in nbd_ioctl nbd C done 71 1658d 1694d 13/26 fixed on 2019/11/06 12:39
linux-6.1 INFO: task hung in nbd_ioctl origin:upstream C 7 27d 393d 0/3 upstream: reported C repro on 2023/04/23 23:29
linux-4.19 INFO: task hung in nbd_ioctl C error 79 468d 1682d 0/1 upstream: reported C repro on 2019/10/12 13:11
upstream INFO: task hung in nbd_ioctl (3) nbd C done unreliable 121 9d22h 1331d 0/26 upstream: reported C repro on 2020/09/28 07:17
linux-4.14 INFO: task hung in nbd_ioctl (3) C inconclusive 12 733d 1285d 0/1 upstream: reported C repro on 2020/11/13 07:37
upstream INFO: task can't die in nbd_ioctl nbd C done 7 37d 1324d 0/26 upstream: reported C repro on 2020/10/05 07:20

Sample crash report:
INFO: task syz-executor107:3989 blocked for more than 143 seconds.
      Not tainted 5.15.156-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor107 state:D stack:    0 pid: 3989 ppid:  3988 flags:0x0000000d
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6376
 schedule+0x11c/0x1c8 kernel/sched/core.c:6459
 schedule_timeout+0xb8/0x344 kernel/time/timer.c:1890
 do_wait_for_common+0x214/0x388 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+0x4c/0x64 kernel/sched/completion.c:138
 flush_workqueue+0x580/0x11c4 kernel/workqueue.c:2882
 nbd_start_device_ioctl drivers/block/nbd.c:1365 [inline]
 __nbd_ioctl drivers/block/nbd.c:1427 [inline]
 nbd_ioctl+0x8c8/0xc2c drivers/block/nbd.c:1467
 blkdev_ioctl+0x3d8/0xbd0 block/ioctl.c:604
 block_ioctl+0xa8/0x114 block/fops.c:493
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffff800014b114e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:311
2 locks held by kworker/u5:0/145:
 #0: ffff0000cbea4138 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
 #1: ffff80001a437c00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285
2 locks held by getty/3718:
 #0: ffff0000d2def098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff800018e132e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158

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


Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/26 03:27 linux-5.15.y c52b9710c83d 8bdc0f22 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in nbd_ioctl
2024/04/26 01:56 linux-5.15.y c52b9710c83d 8bdc0f22 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in nbd_ioctl
2023/06/26 06:58 linux-5.15.y f67653019430 79782afc .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in nbd_ioctl
2023/08/19 16:34 linux-5.15.y f6f7927ac664 d216d8a0 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in nbd_ioctl
2024/04/06 08:19 linux-5.15.y 9465fef4ae35 ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in nbd_ioctl
2024/04/06 08:13 linux-5.15.y 9465fef4ae35 ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in nbd_ioctl
2024/03/17 04:27 linux-5.15.y b95c01af2113 d615901c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in nbd_ioctl
2024/01/31 23:32 linux-5.15.y 6139f2a02fe0 373b66cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in nbd_ioctl
2024/03/29 00:22 linux-5.15.y 9465fef4ae35 e91187ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in nbd_ioctl
2024/03/17 04:05 linux-5.15.y b95c01af2113 d615901c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in nbd_ioctl
2024/02/06 13:03 linux-5.15.y 6139f2a02fe0 6404acf9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in nbd_ioctl
* Struck through repros no longer work on HEAD.