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: 604d, last: 5d11h
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 2194d 2032d 0/1 auto-closed as invalid on 2019/04/28 09:45
linux-4.14 INFO: task hung in iterate_supers 16 1402d 2017d 0/1 auto-closed as invalid on 2021/04/29 12:11
linux-4.19 INFO: task hung in iterate_supers (2) 1 1604d 1604d 0/1 auto-closed as invalid on 2020/10/09 12:15
upstream INFO: task hung in iterate_supers 9p C error 4465 2h50m 2306d 0/28 upstream: reported C repro on 2018/07/10 10:30
linux-6.1 INFO: task hung in iterate_supers 221 2d11h 602d 0/3 upstream: reported on 2023/03/10 21:24
linux-4.14 INFO: task hung in iterate_supers (2) 1 616d 616d 0/1 upstream: reported on 2023/02/24 15:59
linux-4.19 INFO: task hung in iterate_supers 7 1737d 1924d 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 606d 1412d 0/1 upstream: reported syz repro on 2020/12/20 03:38
android-49 INFO: task hung in iterate_supers 19 2256d 2356d 0/3 auto-closed as invalid on 2019/02/25 14:49
android-414 INFO: task hung in iterate_supers (2) 1 2013d 2013d 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 1236d 1232d 0/28 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 (223):
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
2024/10/23 05:41 linux-5.15.y 74cdd62cb470 15fa2979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/10/22 12:41 linux-5.15.y 584a40a22cb9 a93682b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/10/20 19:57 linux-5.15.y 584a40a22cb9 cd6fc0a3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/10/18 18:59 linux-5.15.y 584a40a22cb9 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/10/18 16:58 linux-5.15.y 584a40a22cb9 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/10/13 23:07 linux-5.15.y 3a5928702e71 084d8178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/10/07 10:22 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/10/06 08:02 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/10/04 15:44 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/29 11:30 linux-5.15.y 3a5928702e71 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/28 23:35 linux-5.15.y 3a5928702e71 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/28 19:03 linux-5.15.y 3a5928702e71 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/27 01:25 linux-5.15.y 3a5928702e71 9314348a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/25 00:19 linux-5.15.y 3a5928702e71 5643e0e9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/20 05:54 linux-5.15.y 3a5928702e71 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/20 02:44 linux-5.15.y 3a5928702e71 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/19 07:01 linux-5.15.y 3a5928702e71 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/17 20:40 linux-5.15.y 3a5928702e71 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/16 12:11 linux-5.15.y 3a5928702e71 08d8a733 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/15 14:19 linux-5.15.y 3a5928702e71 08d8a733 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/14 18:06 linux-5.15.y 3a5928702e71 c7e35043 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/13 21:26 linux-5.15.y 3a5928702e71 b58f933c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/13 08:08 linux-5.15.y 3a5928702e71 73e8a465 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/12 17:04 linux-5.15.y 3a5928702e71 60e1a995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/10 09:16 linux-5.15.y 14e468424d3e 784df80e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/09 08:08 linux-5.15.y 14e468424d3e 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/08 16:16 linux-5.15.y 14e468424d3e 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/05 20:16 linux-5.15.y 14e468424d3e 464ac2ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/03 15:14 linux-5.15.y fa93fa65db6e 326f9c5a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/09/01 07:21 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/08/31 00:12 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/08/30 16:34 linux-5.15.y fa93fa65db6e ee2602b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/08/30 09:34 linux-5.15.y fa93fa65db6e ee2602b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/08/29 00:53 linux-5.15.y fa93fa65db6e ef3de9e8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/08/26 20:03 linux-5.15.y fa93fa65db6e 9aee4e0b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/08/24 22:18 linux-5.15.y fa93fa65db6e d7d32352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/08/20 23:33 linux-5.15.y fa93fa65db6e 9f0ab3fb .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/08/19 16:45 linux-5.15.y fa93fa65db6e 9f0ab3fb .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in iterate_supers
2024/10/27 11:34 linux-5.15.y 74cdd62cb470 65e8686b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2024/10/20 03:20 linux-5.15.y 584a40a22cb9 cd6fc0a3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2024/10/10 09:12 linux-5.15.y 3a5928702e71 0278d004 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2024/10/03 09:06 linux-5.15.y 3a5928702e71 a4c7fd36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2024/09/11 17:06 linux-5.15.y 14e468424d3e 8ab55d0e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in iterate_supers
2024/09/09 23:05 linux-5.15.y 14e468424d3e 073f8be2 .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.