syzbot


INFO: task hung in iterate_supers

Status: upstream: reported C repro on 2023/03/08 18:22
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+b2fb36aa868ed8376328@syzkaller.appspotmail.com
First crash: 361d, last: 3d00h
Bug presence (2)
Date Name Commit Repro Result
2023/05/03 linux-5.15.y (ToT) 8a7f2a5c5aa1 C [report] INFO: task hung in iterate_supers
2023/05/03 upstream (ToT) 348551ddaf31 C Didn't crash
Similar bugs (11)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 INFO: task hung in iterate_supers 1 1951d 1789d 0/1 auto-closed as invalid on 2019/04/28 09:45
linux-4.14 INFO: task hung in iterate_supers 16 1159d 1774d 0/1 auto-closed as invalid on 2021/04/29 12:11
linux-4.19 INFO: task hung in iterate_supers (2) 1 1361d 1361d 0/1 auto-closed as invalid on 2020/10/09 12:15
upstream INFO: task hung in iterate_supers 9p C error 2827 8h11m 2063d 0/26 upstream: reported C repro on 2018/07/10 10:30
linux-6.1 INFO: task hung in iterate_supers 88 11d 359d 0/3 upstream: reported on 2023/03/10 21:24
linux-4.14 INFO: task hung in iterate_supers (2) 1 373d 373d 0/1 upstream: reported on 2023/02/24 15:59
linux-4.19 INFO: task hung in iterate_supers 7 1494d 1681d 0/1 auto-closed as invalid on 2020/05/29 21:42
linux-4.19 INFO: task hung in iterate_supers (3) vfs reiserfs ntfs syz 378 363d 1170d 0/1 upstream: reported syz repro on 2020/12/20 03:38
android-49 INFO: task hung in iterate_supers 19 2013d 2113d 0/3 auto-closed as invalid on 2019/02/25 14:49
android-414 INFO: task hung in iterate_supers (2) 1 1770d 1770d 0/1 auto-closed as invalid on 2019/10/25 08:49
upstream INFO: task can't die in iterate_supers (2) ceph fs 1 994d 990d 0/26 auto-closed as invalid on 2021/08/13 03:51
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2023/10/19 02:40 2h25m fix candidate upstream job log (0) log

Sample crash report:
INFO: task syz-executor862:21862 blocked for more than 143 seconds.
      Not tainted 5.15.103-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor862 state:D stack:28032 pid:21862 ppid:  3658 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5023 [inline]
 __schedule+0x1348/0x4610 kernel/sched/core.c:6369
 schedule+0x11b/0x1f0 kernel/sched/core.c:6452
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6511
 rwsem_down_read_slowpath+0x605/0xb40 kernel/locking/rwsem.c:1047
 __down_read_common+0x61/0x2c0 kernel/locking/rwsem.c:1231
 iterate_supers+0xac/0x1e0 fs/super.c:694
 ksys_sync+0xb9/0x1c0 fs/sync.c:102
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f4efe5e5db9
RSP: 002b:00007f4efdd73208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f4efe675298 RCX: 00007f4efe5e5db9
RDX: 00007f4efe5e5db9 RSI: 00007f4efe63c1b4 RDI: 0000000000000081
RBP: 00007f4efe675290 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4efe67529c
R13: 00007ffca4092d0f R14: 00007f4efdd73300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91c320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by klogd/2949:
 #0: ffff8880b9b39698 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
2 locks held by getty/3270:
 #0: ffff8880241fc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002bb32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1da0 drivers/tty/n_tty.c:2147
1 lock held by syz-executor862/21861:
 #0: ffff88801bd7c0e0 (&type->s_umount_key#44/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229
1 lock held by syz-executor862/21862:
 #0: ffff88801bd7c0e0 (&type->s_umount_key#67){.+.+}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:694

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.103-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xf54/0xfa0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </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:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:570

Crashes (100):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/03/19 08:17 linux-5.15.y 8020ae3c051d 7939252e .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/03/01 05:01 linux-5.15.y 458ce51d0356 352ab904 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/02/27 19:16 linux-5.15.y 458ce51d0356 d367cbe5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/02/23 04:40 linux-5.15.y 6139f2a02fe0 8d446f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/02/21 14:57 linux-5.15.y 6139f2a02fe0 3af7dd65 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/02/14 16:06 linux-5.15.y 6139f2a02fe0 d902085f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/02/08 05:19 linux-5.15.y 6139f2a02fe0 6404acf9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/02/07 10:39 linux-5.15.y 6139f2a02fe0 6404acf9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/01/29 00:01 linux-5.15.y 6139f2a02fe0 cc4a4020 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/01/18 13:08 linux-5.15.y ddcaf4999061 239abf84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/01/12 23:20 linux-5.15.y 26c690eff0a5 551587c1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/01/12 17:19 linux-5.15.y 26c690eff0a5 551587c1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/01/11 07:27 linux-5.15.y 26c690eff0a5 00f3cc59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/01/04 08:48 linux-5.15.y d93fa2c78854 28c42cff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/01/02 20:52 linux-5.15.y d93fa2c78854 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/12/28 05:39 linux-5.15.y d93fa2c78854 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/12/21 13:13 linux-5.15.y 1d146b1875fc 4f9530a3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/12/11 15:38 linux-5.15.y 8a1d809b0545 28b24332 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/12/06 14:52 linux-5.15.y 9b91d36ba301 e3299f55 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/12/03 11:56 linux-5.15.y 9b91d36ba301 f819d6f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/11/23 20:53 linux-5.15.y 2a910f4af54d 5b429f39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/11/22 06:36 linux-5.15.y 2a910f4af54d cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/11/15 14:14 linux-5.15.y 80529b4968a8 cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/11/13 08:38 linux-5.15.y 80529b4968a8 6d6dbf8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/11/13 07:15 linux-5.15.y 80529b4968a8 6d6dbf8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/11/04 11:31 linux-5.15.y 12952a23a5da 500bfdc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/11/02 12:20 linux-5.15.y 12952a23a5da 69904c9f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/11/01 15:32 linux-5.15.y 12952a23a5da 69904c9f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/10/28 17:10 linux-5.15.y 12952a23a5da 3c418d72 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/10/16 05:15 linux-5.15.y 02e21884dcf2 f757a323 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/10/09 04:55 linux-5.15.y 1edcec18cfb7 5e837c76 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/09/26 19:09 linux-5.15.y b911329317b4 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/09/24 19:58 linux-5.15.y b911329317b4 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/09/06 21:23 linux-5.15.y 8f790700c974 72324844 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/02/18 14:06 linux-5.15.y 6139f2a02fe0 578f7538 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2024/01/20 16:55 linux-5.15.y ddcaf4999061 9bd8dcda .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2023/12/14 22:56 linux-5.15.y d0fc081c6241 3222d10c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2023/10/29 03:33 linux-5.15.y 12952a23a5da 3c418d72 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2023/10/11 05:07 linux-5.15.y 02e21884dcf2 83165b57 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2023/10/05 00:14 linux-5.15.y b911329317b4 b7d7ff54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2023/10/04 18:35 linux-5.15.y b911329317b4 b7d7ff54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2023/09/06 10:41 linux-5.15.y 8f790700c974 0b6286dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2023/09/05 06:14 linux-5.15.y 8f790700c974 0b6286dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2023/08/27 12:14 linux-5.15.y 5ddfe5cc8716 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/08/23 16:08 linux-5.15.y f6f7927ac664 b81ca3f6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/08/20 15:27 linux-5.15.y f6f7927ac664 d216d8a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/08/16 03:43 linux-5.15.y 24c4de4069cb 39990d51 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/08/12 15:10 linux-5.15.y 24c4de4069cb 39990d51 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/08/12 00:30 linux-5.15.y 24c4de4069cb 39990d51 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/08/04 20:54 linux-5.15.y 38d4ca22a528 cdae481e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/03/19 19:06 linux-5.15.y 8020ae3c051d 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/03/13 22:17 linux-5.15.y 2ddbd0f967b3 026e2200 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/03/08 18:22 linux-5.15.y d9b4a0c83a2d 4fc6d98d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2023/08/20 04:50 linux-5.15.y f6f7927ac664 d216d8a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2023/08/18 07:09 linux-5.15.y f6f7927ac664 74b106b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2023/03/19 19:24 linux-5.15.y 8020ae3c051d 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2023/03/13 17:21 linux-5.15.y 2ddbd0f967b3 026e2200 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
* Struck through repros no longer work on HEAD.