LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: syzbot <syzbot+c9ff4822a62eee994ea3@syzkaller.appspotmail.com>
To: adilger.kernel@dilger.ca, clang-built-linux@googlegroups.com,
	linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
	nathan@kernel.org, ndesaulniers@google.com,
	syzkaller-bugs@googlegroups.com, tytso@mit.edu
Subject: [syzbot] INFO: task hung in ext4_fill_super
Date: Wed, 16 Jun 2021 02:56:21 -0700	[thread overview]
Message-ID: <0000000000004c80e405c4df1a2d@google.com> (raw)

Hello,

syzbot found the following issue on:

HEAD commit:    f21b807c Merge tag 'drm-fixes-2021-06-11' of git://anongit..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=165fca57d00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=30f476588412c065
dashboard link: https://syzkaller.appspot.com/bug?extid=c9ff4822a62eee994ea3
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17d19ce0300000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=108d7988300000

Bisection is inconclusive: the issue happens on the oldest tested release.

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1646b8d0300000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=1546b8d0300000
console output: https://syzkaller.appspot.com/x/log.txt?x=1146b8d0300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c9ff4822a62eee994ea3@syzkaller.appspotmail.com

INFO: task syz-executor768:8567 blocked for more than 143 seconds.
      Not tainted 5.13.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor768 state:D stack:27544 pid: 8567 ppid:  8423 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4339 [inline]
 __schedule+0x916/0x23e0 kernel/sched/core.c:5147
 schedule+0xcf/0x270 kernel/sched/core.c:5226
 schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x168/0x270 kernel/sched/completion.c:138
 kthread_stop+0x17a/0x720 kernel/kthread.c:642
 ext4_fill_super+0x87ac/0xdfa0 fs/ext4/super.c:5190
 mount_bdev+0x34d/0x410 fs/super.c:1368
 legacy_get_tree+0x105/0x220 fs/fs_context.c:592
 vfs_get_tree+0x89/0x2f0 fs/super.c:1498
 do_new_mount fs/namespace.c:2905 [inline]
 path_mount+0x132a/0x1fa0 fs/namespace.c:3235
 do_mount fs/namespace.c:3248 [inline]
 __do_sys_mount fs/namespace.c:3456 [inline]
 __se_sys_mount fs/namespace.c:3433 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3433
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x445b2a
RSP: 002b:00007ffc5efbf598 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffc5efbf5f0 RCX: 0000000000445b2a
RDX: 0000000020000000 RSI: 00000000200000c0 RDI: 00007ffc5efbf5b0
RBP: 00007ffc5efbf5b0 R08: 00007ffc5efbf5f0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000200003f8
R13: 0000000000000003 R14: 0000000000000004 R15: 0000000000000005

Showing all locks held in the system:
1 lock held by khungtaskd/1636:
 #0: ffffffff8bf79620 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6333
2 locks held by in:imklog/8117:
 #0: ffff888015be9770 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:974
 #1: ffff888021bc3958 (&mm->mmap_lock#2){++++}-{3:3}, at: file_ctx security/apparmor/include/file.h:33 [inline]
 #1: ffff888021bc3958 (&mm->mmap_lock#2){++++}-{3:3}, at: aa_file_perm+0x119/0x1170 security/apparmor/file.c:609
1 lock held by syz-executor768/8567:
 #0: ffff88802ac340e0 (&type->s_umount_key#27/1){+.+.}-{3:3}, at: alloc_super+0x1dd/0xab0 fs/super.c:229

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

NMI backtrace for cpu 0
CPU: 0 PID: 1636 Comm: khungtaskd Not tainted 5.13.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd48/0xfb0 kernel/hung_task.c:294
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
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:108 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x1c9/0x250 drivers/acpi/processor_idle.c:513


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

             reply	other threads:[~2021-06-16  9:56 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-16  9:56 syzbot [this message]
2021-06-16 16:22 ` Pavel Skripkin
2021-06-16 18:28   ` syzbot
2021-08-05 14:26 ` Pavel Skripkin
2021-08-05 14:46   ` syzbot
2021-08-06  7:45     ` Pavel Skripkin
2021-08-06 10:14       ` syzbot

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=0000000000004c80e405c4df1a2d@google.com \
    --to=syzbot+c9ff4822a62eee994ea3@syzkaller.appspotmail.com \
    --cc=adilger.kernel@dilger.ca \
    --cc=clang-built-linux@googlegroups.com \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nathan@kernel.org \
    --cc=ndesaulniers@google.com \
    --cc=syzkaller-bugs@googlegroups.com \
    --cc=tytso@mit.edu \
    --subject='Re: [syzbot] INFO: task hung in ext4_fill_super' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).