From: syzbot <syzbot+e525d9be15a106e48379@syzkaller.appspotmail.com>
To: amir73il@gmail.com, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-unionfs@vger.kernel.org,
miklos@szeredi.hu, syzkaller-bugs@googlegroups.com
Subject: [syzbot] [overlayfs?] possible deadlock in iter_file_splice_write (3)
Date: Wed, 13 Mar 2024 16:10:33 -0700 [thread overview]
Message-ID: <000000000000bb26fd061392e1a9@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 09e5c48fea17 Merge tag 'ceph-for-6.8-rc8' of https://githu..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=130a9a3e180000
kernel config: https://syzkaller.appspot.com/x/.config?x=44c92d6f247776b0
dashboard link: https://syzkaller.appspot.com/bug?extid=e525d9be15a106e48379
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/be1396cce3c5/disk-09e5c48f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cd84fbdb0969/vmlinux-09e5c48f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/46bf297bd50b/bzImage-09e5c48f.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e525d9be15a106e48379@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
6.8.0-rc7-syzkaller-00231-g09e5c48fea17 #0 Not tainted
------------------------------------------------------
syz-executor.2/10894 is trying to acquire lock:
ffff8880434f8468 (&pipe->mutex/1){+.+.}-{3:3}, at: iter_file_splice_write+0x335/0x14e0 fs/splice.c:687
but task is already holding lock:
ffff88801e194420 (sb_writers#4){.+.+}-{0:0}, at: do_splice+0xcf0/0x1880 fs/splice.c:1353
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (sb_writers#4){.+.+}-{0:0}:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1641 [inline]
sb_start_write+0x4d/0x1c0 include/linux/fs.h:1777
mnt_want_write+0x3f/0x90 fs/namespace.c:409
ovl_create_object+0x13b/0x370 fs/overlayfs/dir.c:629
lookup_open fs/namei.c:3500 [inline]
open_last_lookups fs/namei.c:3569 [inline]
path_openat+0x1424/0x3240 fs/namei.c:3799
do_filp_open+0x234/0x490 fs/namei.c:3829
do_sys_openat2+0x13e/0x1d0 fs/open.c:1404
do_sys_open fs/open.c:1419 [inline]
__do_sys_openat fs/open.c:1435 [inline]
__se_sys_openat fs/open.c:1430 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1430
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
-> #3 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526
inode_lock_shared include/linux/fs.h:814 [inline]
lookup_slow+0x45/0x70 fs/namei.c:1709
walk_component+0x2e1/0x410 fs/namei.c:2005
lookup_last fs/namei.c:2462 [inline]
path_lookupat+0x16f/0x450 fs/namei.c:2486
filename_lookup+0x255/0x610 fs/namei.c:2515
kern_path+0x35/0x50 fs/namei.c:2623
lookup_bdev+0xc5/0x290 block/bdev.c:1014
resume_store+0x1a0/0x710 kernel/power/hibernate.c:1183
kernfs_fop_write_iter+0x3a4/0x500 fs/kernfs/file.c:334
call_write_iter include/linux/fs.h:2087 [inline]
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xa81/0xcb0 fs/read_write.c:590
ksys_write+0x1a0/0x2c0 fs/read_write.c:643
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
-> #2 (&of->mutex){+.+.}-{3:3}:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154
seq_read_iter+0x3d0/0xd60 fs/seq_file.c:225
call_read_iter include/linux/fs.h:2081 [inline]
new_sync_read fs/read_write.c:395 [inline]
vfs_read+0x978/0xb70 fs/read_write.c:476
ksys_read+0x1a0/0x2c0 fs/read_write.c:619
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
-> #1 (&p->lock){+.+.}-{3:3}:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
seq_read_iter+0xb7/0xd60 fs/seq_file.c:182
proc_reg_read_iter+0x1c3/0x290 fs/proc/inode.c:299
call_read_iter include/linux/fs.h:2081 [inline]
copy_splice_read+0x661/0xb60 fs/splice.c:365
do_splice_read fs/splice.c:985 [inline]
splice_file_to_pipe+0x299/0x500 fs/splice.c:1295
do_sendfile+0x515/0xdc0 fs/read_write.c:1301
__do_sys_sendfile64 fs/read_write.c:1356 [inline]
__se_sys_sendfile64+0x100/0x1e0 fs/read_write.c:1348
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
-> #0 (&pipe->mutex/1){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869
__lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
iter_file_splice_write+0x335/0x14e0 fs/splice.c:687
do_splice_from fs/splice.c:941 [inline]
do_splice+0xd77/0x1880 fs/splice.c:1354
__do_splice fs/splice.c:1436 [inline]
__do_sys_splice fs/splice.c:1652 [inline]
__se_sys_splice+0x331/0x4a0 fs/splice.c:1634
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
other info that might help us debug this:
Chain exists of:
&pipe->mutex/1 --> &ovl_i_mutex_dir_key[depth] --> sb_writers#4
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(sb_writers#4);
lock(&ovl_i_mutex_dir_key[depth]);
lock(sb_writers#4);
lock(&pipe->mutex/1);
*** DEADLOCK ***
1 lock held by syz-executor.2/10894:
#0: ffff88801e194420 (sb_writers#4){.+.+}-{0:0}, at: do_splice+0xcf0/0x1880 fs/splice.c:1353
stack backtrace:
CPU: 1 PID: 10894 Comm: syz-executor.2 Not tainted 6.8.0-rc7-syzkaller-00231-g09e5c48fea17 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869
__lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
iter_file_splice_write+0x335/0x14e0 fs/splice.c:687
do_splice_from fs/splice.c:941 [inline]
do_splice+0xd77/0x1880 fs/splice.c:1354
__do_splice fs/splice.c:1436 [inline]
__do_sys_splice fs/splice.c:1652 [inline]
__se_sys_splice+0x331/0x4a0 fs/splice.c:1634
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7fa65fa7dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa6608b00c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 00007fa65fbabf80 RCX: 00007fa65fa7dda9
RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007fa65faca47a R08: 0000000000000009 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fa65fbabf80 R15: 00007ffc7c0d55f8
</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.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
next reply other threads:[~2024-03-13 23:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-13 23:10 syzbot [this message]
2024-03-14 9:27 ` [syzbot] [overlayfs?] possible deadlock in iter_file_splice_write (3) Miklos Szeredi
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=000000000000bb26fd061392e1a9@google.com \
--to=syzbot+e525d9be15a106e48379@syzkaller.appspotmail.com \
--cc=amir73il@gmail.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-unionfs@vger.kernel.org \
--cc=miklos@szeredi.hu \
--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 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.