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From: Hillf Danton <hdanton@sina.com>
To: syzbot <syzbot+9a5b0ced8b1bfb238b56@syzkaller.appspotmail.com>
Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [kernfs?] possible deadlock in kernfs_fop_llseek
Date: Sat,  6 Apr 2024 07:02:43 +0800	[thread overview]
Message-ID: <20240405230243.1067-1-hdanton@sina.com> (raw)
In-Reply-To: <00000000000098f75506153551a1@google.com>

On Wed, 03 Apr 2024 11:23:26 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel..
> git tree:       upstream
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15c38139180000

Test Al's idea.

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  fe46a7dd189e

--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -639,6 +639,8 @@ static int kernfs_fop_open(struct inode
 	 */
 	if (has_mmap)
 		mutex_init(&of->mutex);
+	else if (file->f_mode & FMODE_WRITE)
+		mutex_init(&of->mutex);
 	else
 		mutex_init(&of->mutex);
 
--

  parent reply	other threads:[~2024-04-05 23:03 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-03 18:23 [syzbot] [kernfs?] possible deadlock in kernfs_fop_llseek syzbot
2024-04-03 23:51 ` syzbot
2024-04-04  6:54   ` Amir Goldstein
2024-04-04  8:11     ` Al Viro
2024-04-04  8:21       ` Al Viro
2024-04-04  8:40         ` Al Viro
2024-04-04  9:33         ` Amir Goldstein
2024-04-04 22:01           ` Al Viro
2024-04-05 10:34             ` Amir Goldstein
2024-04-05  6:51           ` Christoph Hellwig
2024-04-05 11:19             ` Christian Brauner
2024-04-05 13:48               ` Christian Brauner
2024-04-05 14:52                 ` Christoph Hellwig
2024-04-05 15:41             ` Tejun Heo
2024-04-06  3:54             ` Al Viro
2024-04-05 10:47           ` Christian Brauner
2024-04-05 14:48             ` Amir Goldstein
2024-04-06  4:09           ` Al Viro
2024-04-06  5:25             ` Amir Goldstein
2024-04-05 15:08     ` Amir Goldstein
2024-04-05 15:37       ` syzbot
2024-04-05 16:23         ` Al Viro
2024-04-06  5:34           ` Amir Goldstein
2024-04-06  7:05             ` syzbot
2024-04-06  7:11               ` Al Viro
2024-04-06  8:23                 ` Hillf Danton
2024-04-07  0:48                   ` Al Viro
2024-04-06  8:57                 ` Amir Goldstein
2024-04-07  0:50                   ` Al Viro
2024-04-07 11:02                     ` Amir Goldstein
2024-04-09  9:18                     ` Christian Brauner
2024-04-04  0:42 ` Hillf Danton
2024-04-04  1:08   ` syzbot
2024-04-04  2:12 ` Hillf Danton
2024-04-04  2:39   ` syzbot
2024-04-05 23:00 ` Hillf Danton
2024-04-05 23:02   ` syzbot
2024-04-06  0:10     ` Al Viro
2024-04-05 23:02 ` Hillf Danton [this message]
2024-04-06  0:34   ` syzbot

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