From: syzbot <syzbot+9543479984ae9e576000@syzkaller.appspotmail.com>
To: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org,
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
tytso@mit.edu
Subject: [syzbot] possible deadlock in ext4_bmap
Date: Mon, 08 Aug 2022 00:33:22 -0700 [thread overview]
Message-ID: <000000000000967c2805e5b5d4ed@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: ca688bff68bc Add linux-next specific files for 20220808
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=177eb001080000
kernel config: https://syzkaller.appspot.com/x/.config?x=4c20e006003cdecb
dashboard link: https://syzkaller.appspot.com/bug?extid=9543479984ae9e576000
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9543479984ae9e576000@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
5.19.0-next-20220808-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/15950 is trying to acquire lock:
ffff88801b348400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:771 [inline]
ffff88801b348400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_bmap+0x4e/0x460 fs/ext4/inode.c:3157
but task is already holding lock:
ffff88814bede3f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x487/0xc00 fs/jbd2/journal.c:2472
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&journal->j_checkpoint_mutex){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
mutex_lock_io_nested+0x13f/0x1190 kernel/locking/mutex.c:833
__jbd2_log_wait_for_space+0x234/0x460 fs/jbd2/checkpoint.c:110
add_transaction_credits+0xa2d/0xb70 fs/jbd2/transaction.c:298
start_this_handle+0x3ae/0x14a0 fs/jbd2/transaction.c:422
jbd2__journal_start+0x38c/0x910 fs/jbd2/transaction.c:520
__ext4_journal_start_sb+0x3a3/0x490 fs/ext4/ext4_jbd2.c:105
__ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
ext4_dirty_inode+0x9d/0x110 fs/ext4/inode.c:5963
__mark_inode_dirty+0x48b/0x1040 fs/fs-writeback.c:2381
mark_inode_dirty include/linux/fs.h:2467 [inline]
generic_write_end+0x350/0x440 fs/buffer.c:2199
ext4_da_write_end+0x16e/0x9a0 fs/ext4/inode.c:3089
generic_perform_write+0x306/0x560 mm/filemap.c:3749
ext4_buffered_write_iter+0x15b/0x460 fs/ext4/file.c:270
ext4_file_write_iter+0x44a/0x1660 fs/ext4/file.c:679
call_write_iter include/linux/fs.h:2192 [inline]
do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:729
do_iter_write+0x182/0x700 fs/read_write.c:855
vfs_iter_write+0x70/0xa0 fs/read_write.c:896
iter_file_splice_write+0x741/0xc90 fs/splice.c:686
do_splice_from fs/splice.c:764 [inline]
direct_splice_actor+0x110/0x180 fs/splice.c:931
splice_direct_to_actor+0x331/0x8a0 fs/splice.c:886
do_splice_direct+0x1a7/0x270 fs/splice.c:974
do_sendfile+0xb19/0x1270 fs/read_write.c:1249
__do_sys_sendfile64 fs/read_write.c:1311 [inline]
__se_sys_sendfile64 fs/read_write.c:1303 [inline]
__x64_sys_sendfile64+0x149/0x210 fs/read_write.c:1303
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+0x63/0xcd
-> #0 (&sb->s_type->i_mutex_key#8){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3095 [inline]
check_prevs_add kernel/locking/lockdep.c:3214 [inline]
validate_chain kernel/locking/lockdep.c:3829 [inline]
__lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5053
lock_acquire kernel/locking/lockdep.c:5666 [inline]
lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631
down_read+0x98/0x450 kernel/locking/rwsem.c:1499
inode_lock_shared include/linux/fs.h:771 [inline]
ext4_bmap+0x4e/0x460 fs/ext4/inode.c:3157
bmap+0xaa/0x120 fs/inode.c:1799
jbd2_journal_bmap+0xa8/0x180 fs/jbd2/journal.c:971
__jbd2_journal_erase fs/jbd2/journal.c:1784 [inline]
jbd2_journal_flush+0x84f/0xc00 fs/jbd2/journal.c:2490
ext4_ioctl_checkpoint fs/ext4/ioctl.c:1082 [inline]
__ext4_ioctl+0x28fd/0x4ab0 fs/ext4/ioctl.c:1586
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
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+0x63/0xcd
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&journal->j_checkpoint_mutex);
lock(&sb->s_type->i_mutex_key#8);
lock(&journal->j_checkpoint_mutex);
lock(&sb->s_type->i_mutex_key#8);
*** DEADLOCK ***
2 locks held by syz-executor.3/15950:
#0: ffff88814bede170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x15e/0x310 fs/jbd2/transaction.c:904
#1: ffff88814bede3f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x487/0xc00 fs/jbd2/journal.c:2472
stack backtrace:
CPU: 1 PID: 15950 Comm: syz-executor.3 Not tainted 5.19.0-next-20220808-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
<TASK>
__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:2175
check_prev_add kernel/locking/lockdep.c:3095 [inline]
check_prevs_add kernel/locking/lockdep.c:3214 [inline]
validate_chain kernel/locking/lockdep.c:3829 [inline]
__lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5053
lock_acquire kernel/locking/lockdep.c:5666 [inline]
lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631
down_read+0x98/0x450 kernel/locking/rwsem.c:1499
inode_lock_shared include/linux/fs.h:771 [inline]
ext4_bmap+0x4e/0x460 fs/ext4/inode.c:3157
bmap+0xaa/0x120 fs/inode.c:1799
jbd2_journal_bmap+0xa8/0x180 fs/jbd2/journal.c:971
__jbd2_journal_erase fs/jbd2/journal.c:1784 [inline]
jbd2_journal_flush+0x84f/0xc00 fs/jbd2/journal.c:2490
ext4_ioctl_checkpoint fs/ext4/ioctl.c:1082 [inline]
__ext4_ioctl+0x28fd/0x4ab0 fs/ext4/ioctl.c:1586
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
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+0x63/0xcd
RIP: 0033:0x7feb4e689279
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feb4f798168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007feb4e79bf80 RCX: 00007feb4e689279
RDX: 0000000020000000 RSI: 000000004004662b RDI: 0000000000000005
RBP: 00007feb4e6e3189 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc38bb538f R14: 00007feb4f798300 R15: 0000000000022000
</TASK>
---
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.
next reply other threads:[~2022-08-08 7:33 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-08 7:33 syzbot [this message]
2022-08-08 19:02 ` [syzbot] possible deadlock in ext4_bmap syzbot
2022-08-12 2:46 ` Jason Yan
2022-08-20 6:25 ` Eric Biggers
2023-04-30 23:28 ` Theodore Ts'o
[not found] <20220809111035.2393-1-hdanton@sina.com>
2022-08-09 20:01 ` 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=000000000000967c2805e5b5d4ed@google.com \
--to=syzbot+9543479984ae9e576000@syzkaller.appspotmail.com \
--cc=adilger.kernel@dilger.ca \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=syzkaller-bugs@googlegroups.com \
--cc=tytso@mit.edu \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.