From: Al Viro <viro@zeniv.linux.org.uk>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Eric Biggers <ebiggers3@gmail.com>,
Dmitry Vyukov <dvyukov@google.com>,
Kees Cook <keescook@chromium.org>,
syzbot
<bot+e93a80c1bb7c5c56e522461c149f8bf55eab1b2b@syzkaller.appspotmail.com>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>
Subject: Re: [PATCH] fs: Allow opening only regular files during execve().
Date: Mon, 21 Jan 2019 21:18:01 +0000 [thread overview]
Message-ID: <20190121211800.GC2217@ZenIV.linux.org.uk> (raw)
In-Reply-To: <d1e2488f-a969-30d4-5023-6fa85a4e3833@I-love.SAKURA.ne.jp>
On Mon, Jan 21, 2019 at 07:14:39PM +0900, Tetsuo Handa wrote:
> On Tue, Dec 12, 2017 at 2:06 PM, Eric Biggers <ebiggers3@gmail.com> wrote:
> > I'm not sure what the fix will be. Maybe the proc handlers should take a
> > different lock instead of cred_guard_mutex. Or perhaps execve should check that
> > the file is a regular file before it attempts to open it.
>
> We can easily distinguish open() from execve() and open() from others. ;-)
> + /* The file or a script interpreter has to be a regular file. */
> + if (unlikely(current->in_execve && !S_ISREG(inode->i_mode))) {
> + error = -EACCES;
> + goto cleanup_file;
> + }
We are *NOT* going to use current->in_execve to propagate that information.
Come up with a cleaner solution, if you care, but this one is a non-starter.
Too ugly to live. Sorry.
next prev parent reply other threads:[~2019-01-21 21:18 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <001a113f711ae2110c055f45acb8@google.com>
2017-12-02 8:12 ` possible deadlock in seq_read syzbot
2017-12-03 22:02 ` syzbot
2017-12-12 22:06 ` Eric Biggers
2017-12-27 18:30 ` Dmitry Vyukov
2018-08-27 18:20 ` Kees Cook
2018-08-27 20:57 ` Dmitry Vyukov
2019-01-21 10:14 ` [PATCH] fs: Allow opening only regular files during execve() Tetsuo Handa
2019-01-21 20:24 ` Kees Cook
2019-01-21 21:18 ` Al Viro [this message]
2019-01-22 0:50 ` [PATCH v2] " Tetsuo Handa
2019-01-28 23:42 ` Andrew Morton
2019-02-12 2:01 ` Tetsuo Handa
2019-02-12 5:26 ` Tetsuo Handa
2019-02-19 9:51 ` Tetsuo Handa
2019-01-22 0:51 ` [PATCH] " Kees Cook
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