From: syzbot <syzbot+c18f2f6a7b08c51e3025@syzkaller.appspotmail.com>
To: linux-kernel@vger.kernel.org, linux-unionfs@vger.kernel.org,
miklos@szeredi.hu, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] possible deadlock in ovl_maybe_copy_up
Date: Sat, 03 Apr 2021 12:18:20 -0700 [thread overview]
Message-ID: <000000000000df47be05bf165394@google.com> (raw)
In-Reply-To: <000000000000c5b77105b4c3546e@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: 454c576c Add linux-next specific files for 20210401
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1616e07ed00000
kernel config: https://syzkaller.appspot.com/x/.config?x=920cc274cae812a5
dashboard link: https://syzkaller.appspot.com/bug?extid=c18f2f6a7b08c51e3025
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13da365ed00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13ca9d16d00000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c18f2f6a7b08c51e3025@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
5.12.0-rc5-next-20210401-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor144/9166 is trying to acquire lock:
ffff888144cf0460 (sb_writers#5){.+.+}-{0:0}, at: ovl_maybe_copy_up+0x11f/0x190 fs/overlayfs/copy_up.c:995
but task is already holding lock:
ffff8880256d42c0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x3a8/0x17e0 security/integrity/ima/ima_main.c:253
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&iint->mutex){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:949 [inline]
__mutex_lock+0x139/0x1120 kernel/locking/mutex.c:1096
process_measurement+0x3a8/0x17e0 security/integrity/ima/ima_main.c:253
ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:499
do_open fs/namei.c:3361 [inline]
path_openat+0x15b5/0x27e0 fs/namei.c:3492
do_filp_open+0x17e/0x3c0 fs/namei.c:3519
do_sys_openat2+0x16d/0x420 fs/open.c:1187
do_sys_open fs/open.c:1203 [inline]
__do_sys_open fs/open.c:1211 [inline]
__se_sys_open fs/open.c:1207 [inline]
__x64_sys_open+0x119/0x1c0 fs/open.c:1207
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #0 (sb_writers#5){.+.+}-{0:0}:
check_prev_add kernel/locking/lockdep.c:2938 [inline]
check_prevs_add kernel/locking/lockdep.c:3061 [inline]
validate_chain kernel/locking/lockdep.c:3676 [inline]
__lock_acquire+0x2a17/0x5230 kernel/locking/lockdep.c:4902
lock_acquire kernel/locking/lockdep.c:5512 [inline]
lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5477
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1758 [inline]
sb_start_write include/linux/fs.h:1828 [inline]
mnt_want_write+0x6e/0x3e0 fs/namespace.c:375
ovl_maybe_copy_up+0x11f/0x190 fs/overlayfs/copy_up.c:995
ovl_open+0xba/0x270 fs/overlayfs/file.c:149
do_dentry_open+0x4b9/0x11b0 fs/open.c:826
vfs_open fs/open.c:940 [inline]
dentry_open+0x132/0x1d0 fs/open.c:956
ima_calc_file_hash+0x2d2/0x4b0 security/integrity/ima/ima_crypto.c:557
ima_collect_measurement+0x4ca/0x570 security/integrity/ima/ima_api.c:252
process_measurement+0xd1c/0x17e0 security/integrity/ima/ima_main.c:330
ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:499
do_open fs/namei.c:3361 [inline]
path_openat+0x15b5/0x27e0 fs/namei.c:3492
do_filp_open+0x17e/0x3c0 fs/namei.c:3519
do_sys_openat2+0x16d/0x420 fs/open.c:1187
do_sys_open fs/open.c:1203 [inline]
__do_sys_open fs/open.c:1211 [inline]
__se_sys_open fs/open.c:1207 [inline]
__x64_sys_open+0x119/0x1c0 fs/open.c:1207
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&iint->mutex);
lock(sb_writers#5);
lock(&iint->mutex);
lock(sb_writers#5);
*** DEADLOCK ***
1 lock held by syz-executor144/9166:
#0: ffff8880256d42c0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x3a8/0x17e0 security/integrity/ima/ima_main.c:253
stack backtrace:
CPU: 1 PID: 9166 Comm: syz-executor144 Not tainted 5.12.0-rc5-next-20210401-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
check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2129
check_prev_add kernel/locking/lockdep.c:2938 [inline]
check_prevs_add kernel/locking/lockdep.c:3061 [inline]
validate_chain kernel/locking/lockdep.c:3676 [inline]
__lock_acquire+0x2a17/0x5230 kernel/locking/lockdep.c:4902
lock_acquire kernel/locking/lockdep.c:5512 [inline]
lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5477
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1758 [inline]
sb_start_write include/linux/fs.h:1828 [inline]
mnt_want_write+0x6e/0x3e0 fs/namespace.c:375
ovl_maybe_copy_up+0x11f/0x190 fs/overlayfs/copy_up.c:995
ovl_open+0xba/0x270 fs/overlayfs/file.c:149
do_dentry_open+0x4b9/0x11b0 fs/open.c:826
vfs_open fs/open.c:940 [inline]
dentry_open+0x132/0x1d0 fs/open.c:956
ima_calc_file_hash+0x2d2/0x4b0 security/integrity/ima/ima_crypto.c:557
ima_collect_measurement+0x4ca/0x570 security/integrity/ima/ima_api.c:252
process_measurement+0xd1c/0x17e0 security/integrity/ima/ima_main.c:330
ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:499
do_open fs/namei.c:3361 [inline]
path_openat+0x15b5/0x27e0 fs/namei.c:3492
do_filp_open+0x17e/0x3c0 fs/namei.c:3519
do_sys_openat2+0x16d/0x420 fs/open.c:1187
do_sys_open fs/open.c:1203 [inline]
__do_sys_open fs/open.c:1211 [inline]
__se_sys_open fs/open.c:1207 [inline]
__x64_sys_open+0x119/0x1c0 fs/open.c:1207
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x446109
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe4412f12f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00000000004cb4c0 RCX: 0000000000446109
RDX: 0000000000000000 RSI: 0000000000000007 RDI: 00000000200001c0
RBP: 000000000049b06c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 69662f7375622f2e
R13: 79706f636174656d R14: 0079616c7265766f R15: 00000000004cb4c8
next prev parent reply other threads:[~2021-04-03 19:18 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-23 10:05 possible deadlock in ovl_maybe_copy_up syzbot
2021-04-03 19:18 ` syzbot [this message]
2021-04-04 8:10 ` [syzbot] " Amir Goldstein
[not found] ` <20210618040135.950-1-hdanton@sina.com>
2021-06-22 2:32 ` Mimi Zohar
2021-06-22 4:51 ` Amir Goldstein
2021-06-22 11:40 ` Mimi Zohar
[not found] ` <20210622065340.1322-1-hdanton@sina.com>
2021-06-22 8:53 ` Amir Goldstein
2023-06-06 9:30 ` 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=000000000000df47be05bf165394@google.com \
--to=syzbot+c18f2f6a7b08c51e3025@syzkaller.appspotmail.com \
--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.