From: Christoph Hellwig <hch@infradead.org>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>,
linux-fsdevel@vger.kernel.org, xfs@oss.sgi.com
Subject: Re: inode_permission NULL pointer dereference in 3.13-rc1
Date: Mon, 25 Nov 2013 08:06:48 -0800 [thread overview]
Message-ID: <20131125160648.GA4933@infradead.org> (raw)
In-Reply-To: <20131124152758.GL10323@ZenIV.linux.org.uk>
On Sun, Nov 24, 2013 at 03:27:58PM +0000, Al Viro wrote:
> which seems to leave two candidates - follow_dotdot_rcu() and path_init(),
> both setting nd->inode to nd->path.dentry->d_inode...
>
> Could you try to reproduce it with something like
> if (read_seqretry(&mount_lock, nd->m_seq))
> goto failed;
> slapped before the success exit in follow_dotdot_rcu(), just to see if
> we are hitting some races with umount here?
Still reproducable with the diff below. Fixed by reverting the RCU'd
vfsmounts.
diff --git a/fs/namei.c b/fs/namei.c
index 8f77a8c..856e4d5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1158,6 +1158,10 @@ static int follow_dotdot_rcu(struct nameidata *nd)
}
follow_mount_rcu(nd);
nd->inode = nd->path.dentry->d_inode;
+
+ if (read_seqretry(&mount_lock, nd->m_seq))
+ goto failed;
+
return 0;
failed:
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next prev parent reply other threads:[~2013-11-25 16:07 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-24 14:04 inode_permission NULL pointer dereference in 3.13-rc1 Christoph Hellwig
2013-11-24 15:27 ` Al Viro
2013-11-25 16:06 ` Christoph Hellwig [this message]
2013-11-26 13:11 ` Al Viro
2013-11-26 14:12 ` Christoph Hellwig
2013-11-27 6:43 ` Al Viro
2013-11-27 10:09 ` Christoph Hellwig
2013-11-28 16:26 ` Al Viro
2013-11-28 21:23 ` Al Viro
2013-11-28 22:51 ` Dave Chinner
2013-11-28 23:44 ` Al Viro
2013-11-29 1:46 ` Dave Chinner
2013-11-29 2:07 ` Al Viro
2013-11-29 2:17 ` Linus Torvalds
2013-11-29 2:07 ` Linus Torvalds
2013-11-29 2:41 ` Al Viro
2013-11-29 3:59 ` Al Viro
2013-11-29 4:06 ` Al Viro
2013-11-29 4:14 ` Al Viro
2013-11-29 6:59 ` Al Viro
2013-11-29 19:44 ` Greg KH
2013-11-29 20:17 ` Linus Torvalds
2013-11-29 23:55 ` Al Viro
2013-11-30 0:18 ` Linus Torvalds
2013-11-30 15:09 ` [GIT PULL] " Theodore Ts'o
2013-11-30 15:13 ` Theodore Ts'o
2013-11-27 21:51 ` Dave Chinner
2013-11-28 15:21 ` Theodore Ts'o
2013-11-28 15:36 ` Theodore Ts'o
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=20131125160648.GA4933@infradead.org \
--to=hch@infradead.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=viro@ZenIV.linux.org.uk \
--cc=xfs@oss.sgi.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox