[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAHk-=wg9e5PDG-y-j6uryc0RCbfZ36yB0a8qBb2hCWNrH4r_3g@mail.gmail.com>
Date: Sat, 9 Nov 2019 08:55:38 -0800
From: Linus Torvalds <torvalds@...ux-foundation.org>
To: Al Viro <viro@...iv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@...ldses.org>,
Ritesh Harjani <riteshh@...ux.ibm.com>,
linux-fsdevel <linux-fsdevel@...r.kernel.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
wugyuan@...ibm.com, Jeff Layton <jlayton@...nel.org>,
hsiangkao@....com, Jan Kara <jack@...e.cz>,
Christoph Hellwig <hch@....de>
Subject: Re: [PATCH][RFC] race in exportfs_decode_fh()
On Fri, Nov 8, 2019 at 7:13 PM Al Viro <viro@...iv.linux.org.uk> wrote:
>
> We have derived the parent from fhandle, we have a disconnected dentry for child,
> we go look for the name. We even find it. Now, we want to look it up. And
> some bastard goes and unlinks it, just as we are trying to lock the parent.
> We do a lookup, and get a negative dentry. Then we unlock the parent... and
> some other bastard does e.g. mkdir with the same name. OK, nresult->d_inode
> is not NULL (anymore). It has fuck-all to do with the original fhandle
> (different inumber, etc.) but we happily accept it.
No arguments with your patch, although I doubt that this case has
actually ever happened in practice ;)
Linus
Powered by blists - more mailing lists