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WARNING: lock held when returning to user space in ovl_write_iter

Status: fixed on 2020/04/15 17:19
Subsystems: overlayfs
[Documentation on labels]
Reported-by: syzbot+9331a354f4f624a52a55@syzkaller.appspotmail.com
Fix commit: c853680453ac ovl: fix lockdep warning for async write
First crash: 1512d, last: 1495d
Cause bisection: introduced by (bisect log) :
commit 2406a307ac7ddfd7effeeaff6947149ec6a95b4e
Author: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Date: Wed Nov 20 09:45:26 2019 +0000

  ovl: implement async IO routines

Crash: WARNING: lock held when returning to user space in ovl_write_iter (log)
Repro: C syz .config
  
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
WARNING: lock held when returning to user space in ovl_write_iter 2 (4) 2020/03/13 08:53
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2020/03/13 08:53 18m miklos@szeredi.hu patch git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 63623fd4 OK
2020/03/12 15:30 19m miklos@szeredi.hu patch git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 63623fd4 OK

Sample crash report:
================================================
WARNING: lock held when returning to user space!
5.6.0-rc3-syzkaller #0 Not tainted
------------------------------------------------
syz-executor005/10349 is leaving the kernel with locks still held!
1 lock held by syz-executor005/10349:
 #0: ffff888214fd6428 (sb_writers#4){.+.+}, at: file_start_write include/linux/fs.h:2903 [inline]
 #0: ffff888214fd6428 (sb_writers#4){.+.+}, at: ovl_write_iter+0xcc1/0x1090 fs/overlayfs/file.c:348

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/03/05 06:14 upstream 63623fd44972 c88c7b75 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/03/03 18:19 upstream 63623fd44972 c88c7b75 .config console log report syz C ci-upstream-kasan-gce-root
2020/03/01 09:35 upstream 63623fd44972 c88c7b75 .config console log report syz C ci-upstream-kasan-gce-smack-root
2020/03/16 18:14 linux-next 770fbb32d34e 749688d2 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2020/02/28 07:17 linux-next bdc5461b23ca 59b57593 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2020/02/28 06:30 linux-next bdc5461b23ca 59b57593 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.