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: 500d, last: 1d02h
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 2090d 1928d 0/1 auto-closed as invalid on 2019/04/28 09:45
linux-4.14 INFO: task hung in iterate_supers 16 1298d 1913d 0/1 auto-closed as invalid on 2021/04/29 12:11
linux-4.19 INFO: task hung in iterate_supers (2) 1 1500d 1500d 0/1 auto-closed as invalid on 2020/10/09 12:15
upstream INFO: task hung in iterate_supers 9p C error 3785 11h35m 2202d 0/27 upstream: reported C repro on 2018/07/10 10:30
linux-6.1 INFO: task hung in iterate_supers 141 2d12h 498d 0/3 upstream: reported on 2023/03/10 21:24
linux-4.14 INFO: task hung in iterate_supers (2) 1 512d 512d 0/1 upstream: reported on 2023/02/24 15:59
linux-4.19 INFO: task hung in iterate_supers 7 1633d 1820d 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 502d 1309d 0/1 upstream: reported syz repro on 2020/12/20 03:38
android-49 INFO: task hung in iterate_supers 19 2152d 2252d 0/3 auto-closed as invalid on 2019/02/25 14:49
android-414 INFO: task hung in iterate_supers (2) 1 1909d 1909d 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 1133d 1129d 0/27 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 OK (0) job log log

Sample crash report:
INFO: task syz-executor240:21756 blocked for more than 143 seconds.
      Not tainted 5.15.158-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor240 state:D stack:26912 pid:21756 ppid:  3537 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
 rwsem_down_read_slowpath+0x605/0xb40 kernel/locking/rwsem.c:1055
 __down_read_common kernel/locking/rwsem.c:1239 [inline]
 __down_read kernel/locking/rwsem.c:1252 [inline]
 down_read+0x9a/0x2e0 kernel/locking/rwsem.c:1500
 iterate_supers+0xac/0x1e0 fs/super.c:703
 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+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2322d04039
RSP: 002b:00007f2322cc0218 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f2322d941c8 RCX: 00007f2322d04039
RDX: 00007f2322d04039 RSI: 0000000000000000 RDI: 0000000000000080
RBP: 00007f2322d941c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2322d5a31c
R13: 00007f2322d5a00f R14: 0030656c69662f2e R15: 64663d736e617274
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by klogd/2951:
 #0: ffff8880b9b3a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
2 locks held by getty/3265:
 #0: ffff88814ab6e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002bab2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
1 lock held by syz-executor240/21756:
 #0: ffff88801aa120e0 (&type->s_umount_key#71){.+.+}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
1 lock held by syz-executor240/21757:
 #0: ffff88801aa120e0 (&type->s_umount_key#70/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.158-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 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+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
 </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 (153):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/12 10:44 linux-5.15.y 284087d4f7d5 9026e142 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
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
2024/05/02 12:09 linux-5.15.y b925f60c6ee7 3ba885bc .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2024/07/19 18:46 linux-5.15.y 7c6d66f0266f 890ce4f3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/07/15 03:18 linux-5.15.y f45bea23c39c eaeb5c15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/07/12 10:51 linux-5.15.y f45bea23c39c eaeb5c15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/07/09 05:12 linux-5.15.y f45bea23c39c bc23a442 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/07/05 10:12 linux-5.15.y f45bea23c39c 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/06/23 07:48 linux-5.15.y 4878aadf2d15 edc5149a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/06/21 03:10 linux-5.15.y 4878aadf2d15 dac2aa43 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/06/13 20:22 linux-5.15.y c61bd26ae81a a9616ff5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/06/09 17:38 linux-5.15.y c61bd26ae81a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/06/08 11:05 linux-5.15.y c61bd26ae81a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/06/06 12:55 linux-5.15.y c61bd26ae81a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/30 01:15 linux-5.15.y c61bd26ae81a 34889ee3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/26 15:25 linux-5.15.y c61bd26ae81a a10a183e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/23 13:54 linux-5.15.y 83655231580b 4c2072ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/22 15:07 linux-5.15.y 83655231580b 4d098039 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/22 11:35 linux-5.15.y 83655231580b 4d098039 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/21 15:12 linux-5.15.y 83655231580b 4c0d3ee3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/17 14:06 linux-5.15.y 83655231580b a12e99e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/16 08:09 linux-5.15.y 284087d4f7d5 ef5d53ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/13 19:06 linux-5.15.y 284087d4f7d5 9026e142 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/13 05:48 linux-5.15.y 284087d4f7d5 9026e142 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/05 19:50 linux-5.15.y 284087d4f7d5 610f2a54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/05 15:55 linux-5.15.y 284087d4f7d5 610f2a54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/05/05 05:22 linux-5.15.y 284087d4f7d5 610f2a54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/04/28 11:18 linux-5.15.y b925f60c6ee7 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/04/26 21:07 linux-5.15.y c52b9710c83d 059e9963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/04/23 17:48 linux-5.15.y c52b9710c83d 21339d7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/04/21 20:05 linux-5.15.y c52b9710c83d af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/04/19 22:22 linux-5.15.y c52b9710c83d af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/04/15 09:23 linux-5.15.y fa3df276cd36 c8349e48 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/04/14 22:18 linux-5.15.y fa3df276cd36 c8349e48 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/04/13 12:11 linux-5.15.y cdfd0a7f0139 c8349e48 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/04/07 22:52 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 iterate_supers
2024/04/02 02:40 linux-5.15.y 9465fef4ae35 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/04/01 00:31 linux-5.15.y 9465fef4ae35 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/03/31 22:26 linux-5.15.y 9465fef4ae35 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/03/31 16:14 linux-5.15.y 9465fef4ae35 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/03/27 17:59 linux-5.15.y 9465fef4ae35 454571b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/03/26 15:50 linux-5.15.y b95c01af2113 bcd9b39f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/03/24 21:53 linux-5.15.y b95c01af2113 0ea90952 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/03/24 02:20 linux-5.15.y b95c01af2113 0ea90952 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/07/20 05:25 linux-5.15.y 7c6d66f0266f 890ce4f3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2024/05/04 05:53 linux-5.15.y 284087d4f7d5 610f2a54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2024/03/28 22:50 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 iterate_supers
2024/03/22 16:46 linux-5.15.y b95c01af2113 4b6cdce6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 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
* Struck through repros no longer work on HEAD.