From: syzbot <syzbot+fadc0aaf497e6a493b9f@syzkaller.appspotmail.com>
To: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
song@kernel.org, syzkaller-bugs@googlegroups.com
Subject: [syzbot] possible deadlock in md_open
Date: Tue, 24 Aug 2021 11:19:21 -0700 [thread overview]
Message-ID: <00000000000034b9ee05ca522caa@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 372b2891c15a Add linux-next specific files for 20210824
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=124dca75300000
kernel config: https://syzkaller.appspot.com/x/.config?x=18ce42745c8b0dd6
dashboard link: https://syzkaller.appspot.com/bug?extid=fadc0aaf497e6a493b9f
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13b10d05300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13fa60fe300000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fadc0aaf497e6a493b9f@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc7-next-20210824-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor325/6558 is trying to acquire lock:
ffff888013f90230 (&mddev->open_mutex){+.+.}-{3:3}, at: md_open+0xfd/0x2e0 drivers/md/md.c:7815
but task is already holding lock:
ffff888077ce3118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb60 fs/block_dev.c:1227
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:596 [inline]
__mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729
bd_register_pending_holders+0x2c/0x470 block/holder.c:160
device_add_disk+0x75e/0xfd0 block/genhd.c:505
add_disk include/linux/genhd.h:221 [inline]
md_alloc+0x91d/0x1150 drivers/md/md.c:5707
md_probe+0x69/0x70 drivers/md/md.c:5738
blk_request_module+0x111/0x1d0 block/genhd.c:667
blkdev_get_no_open+0x178/0x1e0 fs/block_dev.c:1150
blkdev_get_by_dev.part.0+0x22/0xb60 fs/block_dev.c:1214
blkdev_get_by_dev+0x6b/0x80 fs/block_dev.c:1267
swsusp_check+0x4d/0x270 kernel/power/swap.c:1525
software_resume.part.0+0x102/0x1f0 kernel/power/hibernate.c:977
software_resume kernel/power/hibernate.c:86 [inline]
resume_store+0x161/0x190 kernel/power/hibernate.c:1179
kobj_attr_store+0x50/0x80 lib/kobject.c:856
sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:139
kernfs_fop_write_iter+0x342/0x500 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2163 [inline]
new_sync_write+0x429/0x660 fs/read_write.c:511
vfs_write+0x7cf/0xae0 fs/read_write.c:598
ksys_write+0x12d/0x250 fs/read_write.c:651
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #0 (&mddev->open_mutex){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3051 [inline]
check_prevs_add kernel/locking/lockdep.c:3174 [inline]
validate_chain kernel/locking/lockdep.c:3789 [inline]
__lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015
lock_acquire kernel/locking/lockdep.c:5625 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
__mutex_lock_common kernel/locking/mutex.c:596 [inline]
__mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729
md_open+0xfd/0x2e0 drivers/md/md.c:7815
blkdev_get_whole+0x99/0x2a0 fs/block_dev.c:1079
blkdev_get_by_dev.part.0+0x354/0xb60 fs/block_dev.c:1234
blkdev_get_by_dev+0x6b/0x80 fs/block_dev.c:1267
swsusp_check+0x4d/0x270 kernel/power/swap.c:1525
software_resume.part.0+0x102/0x1f0 kernel/power/hibernate.c:977
software_resume kernel/power/hibernate.c:86 [inline]
resume_store+0x161/0x190 kernel/power/hibernate.c:1179
kobj_attr_store+0x50/0x80 lib/kobject.c:856
sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:139
kernfs_fop_write_iter+0x342/0x500 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2163 [inline]
new_sync_write+0x429/0x660 fs/read_write.c:511
vfs_write+0x7cf/0xae0 fs/read_write.c:598
ksys_write+0x12d/0x250 fs/read_write.c:651
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&disk->open_mutex);
lock(&mddev->open_mutex);
lock(&disk->open_mutex);
lock(&mddev->open_mutex);
*** DEADLOCK ***
5 locks held by syz-executor325/6558:
#0: ffff88807f6bc460 (sb_writers#6){.+.+}-{0:0}, at: ksys_write+0x12d/0x250 fs/read_write.c:651
#1: ffff88801a6a3488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x287/0x500 fs/kernfs/file.c:287
#2: ffff8881441a6830 (kn->active#90){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2ab/0x500 fs/kernfs/file.c:288
#3: ffffffff8b84fc68 (system_transition_mutex/1){+.+.}-{3:3}, at: software_resume.part.0+0x19/0x1f0 kernel/power/hibernate.c:932
#4: ffff888077ce3118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb60 fs/block_dev.c:1227
stack backtrace:
CPU: 1 PID: 6558 Comm: syz-executor325 Not tainted 5.14.0-rc7-next-20210824-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2131
check_prev_add kernel/locking/lockdep.c:3051 [inline]
check_prevs_add kernel/locking/lockdep.c:3174 [inline]
validate_chain kernel/locking/lockdep.c:3789 [inline]
__lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015
lock_acquire kernel/locking/lockdep.c:5625 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
__mutex_lock_common kernel/locking/mutex.c:596 [inline]
__mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729
md_open+0xfd/0x2e0 drivers/md/md.c:7815
blkdev_get_whole+0x99/0x2a0 fs/block_dev.c:1079
blkdev_get_by_dev.part.0+0x354/0xb60 fs/block_dev.c:1234
blkdev_get_by_dev+0x6b/0x80 fs/block_dev.c:1267
swsusp_check+0x4d/0x270 kernel/power/swap.c:1525
software_resume.part.0+0x102/0x1f0 kernel/power/hibernate.c:977
software_resume kernel/power/hibernate.c:86 [inline]
resume_store+0x161/0x190 kernel/power/hibernate.c:1179
kobj_attr_store+0x50/0x80 lib/kobject.c:856
sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:139
kernfs_fop_write_iter+0x342/0x500 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2163 [inline]
new_sync_write+0x429/0x660 fs/read_write.c:511
vfs_write+0x7cf/0xae0 fs/read_write.c:598
ksys_write+0x12d/0x250 fs/read_write.c:651
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x43f0e9
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd59408358 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043f0e9
RDX: 000000000000fdef RSI: 0000000020000000 RDI: 0000000000000003
RBP: 0000000000402e40 R08: 0000000000000012 R09: 0000000000400488
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402ed0
R13: 0000000000000000 R14: 00000000004ad018 R15: 0000000000400488
---
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.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches
next reply other threads:[~2021-08-24 18:19 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-24 18:19 syzbot [this message]
2021-08-24 23:12 ` [syzbot] possible deadlock in md_open Song Liu
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=00000000000034b9ee05ca522caa@google.com \
--to=syzbot+fadc0aaf497e6a493b9f@syzkaller.appspotmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-raid@vger.kernel.org \
--cc=song@kernel.org \
--cc=syzkaller-bugs@googlegroups.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox