linux-security-module.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Christian Brauner <christian.brauner@ubuntu.com>
To: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
	Andrew Morton <akpm@linux-foundation.org>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	Eric Biggers <ebiggers3@gmail.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	linux-fsdevel@vger.kernel.org,
	linux-security-module@vger.kernel.org, linux-api@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/4] exec: Change uselib(2) IS_SREG() failure to EACCES
Date: Mon, 18 May 2020 15:02:51 +0200	[thread overview]
Message-ID: <20200518130251.zih2s32q2rxhxg6f@wittgenstein> (raw)
In-Reply-To: <20200518055457.12302-2-keescook@chromium.org>

On Sun, May 17, 2020 at 10:54:54PM -0700, Kees Cook wrote:
> Change uselib(2)' S_ISREG() error return to EACCES instead of EINVAL so
> the behavior matches execve(2), and the seemingly documented value.
> The "not a regular file" failure mode of execve(2) is explicitly
> documented[1], but it is not mentioned in uselib(2)[2] which does,
> however, say that open(2) and mmap(2) errors may apply. The documentation
> for open(2) does not include a "not a regular file" error[3], but mmap(2)
> does[4], and it is EACCES.
> 
> [1] http://man7.org/linux/man-pages/man2/execve.2.html#ERRORS
> [2] http://man7.org/linux/man-pages/man2/uselib.2.html#ERRORS
> [3] http://man7.org/linux/man-pages/man2/open.2.html#ERRORS
> [4] http://man7.org/linux/man-pages/man2/mmap.2.html#ERRORS
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>

This is all extremely weird.
uselib has been deprected since forever basically which makes me doubt
this matters much but:
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>

Also - gulp (puts on flame proof suit) - may I suggest we check if there
are any distros out there that still set CONFIG_USELIB=y and if not do
what we did with the sysctl syscall and remove it? If someone yells we
can always backpaddle...

Christian

  reply	other threads:[~2020-05-18 13:03 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-18  5:54 [PATCH 0/4] Relocate execve() sanity checks Kees Cook
2020-05-18  5:54 ` [PATCH 1/4] exec: Change uselib(2) IS_SREG() failure to EACCES Kees Cook
2020-05-18 13:02   ` Christian Brauner [this message]
2020-05-18 14:43     ` Jann Horn
2020-05-18 14:46       ` Christian Brauner
2020-05-18 23:57         ` Eric W. Biederman
2020-05-19  8:11           ` Christian Brauner
2020-05-19  8:37           ` Andreas Schwab
2020-05-19 11:56             ` Eric W. Biederman
2020-05-19 12:12               ` Andreas Schwab
2020-05-19 12:28                 ` Eric W. Biederman
2020-05-19 13:29                   ` Christian Brauner
2020-05-19 14:49                     ` Eric W. Biederman
2020-05-19 13:13               ` Christian Brauner
2020-05-19 14:32                 ` Geert Uytterhoeven
2020-05-19 14:47                   ` Christian Brauner
2020-05-18  5:54 ` [PATCH 2/4] exec: Relocate S_ISREG() check Kees Cook
     [not found]   ` <20200525091420.GI12456@shao2-debian>
2020-06-04 22:45     ` [exec] 166d03c9ec: ltp.execveat02.fail Kees Cook
2020-06-05  2:57     ` Kees Cook
2020-05-18  5:54 ` [PATCH 3/4] exec: Relocate path_noexec() check Kees Cook
2020-05-18  5:54 ` [PATCH 4/4] fs: Include FMODE_EXEC when converting flags to f_mode Kees Cook
2020-05-19 15:06 ` [PATCH 0/4] Relocate execve() sanity checks Eric W. Biederman
2020-05-19 16:26   ` Kees Cook
2020-05-19 17:41     ` Eric W. Biederman
2020-05-19 17:56       ` Kees Cook
2020-05-19 18:42         ` Eric W. Biederman
2020-05-19 21:17           ` Kees Cook
2020-05-19 22:58             ` John Johansen

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=20200518130251.zih2s32q2rxhxg6f@wittgenstein \
    --to=christian.brauner@ubuntu.com \
    --cc=akpm@linux-foundation.org \
    --cc=dvyukov@google.com \
    --cc=ebiggers3@gmail.com \
    --cc=keescook@chromium.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=penguin-kernel@I-love.SAKURA.ne.jp \
    --cc=viro@zeniv.linux.org.uk \
    /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;
as well as URLs for NNTP newsgroup(s).