From: Luis Chamberlain <mcgrof@kernel.org>
To: Christian Brauner <christian@brauner.io>
Cc: akpm@linux-foundation.org, keescook@chromium.org,
linux-kernel@vger.kernel.org, ebiederm@xmission.com,
joe.lawrence@redhat.com, longman@redhat.com,
linux@dominikbrodowski.net, viro@zeniv.linux.org.uk,
adobriyan@gmail.com, linux-api@vger.kernel.org
Subject: Re: [RFC PATCH v4 3/3] sysctl: return -EINVAL if val violates minmax
Date: Mon, 11 Feb 2019 11:50:25 -0800 [thread overview]
Message-ID: <20190211195025.GT11489@garbanzo.do-not-panic.com> (raw)
In-Reply-To: <20190210203943.8227-4-christian@brauner.io>
On Sun, Feb 10, 2019 at 09:39:43PM +0100, Christian Brauner wrote:
> Currently when userspace gives us a values that overflow e.g. file-max and
> other callers of __do_proc_doulongvec_minmax() we simply
> ignore the new value and leave the current value untouched. This can be
> problematic as it gives the illusion that the limit has indeed be bumped
> when in fact it failed.
> This commit makes sure to return EINVAL when an overflow is detected.
> Please note that this is a userspace facing change.
>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Luis
> Signed-off-by: Christian Brauner <christian@brauner.io>
> ---
> /* Changelog */
> v4:
> - patch introduced
>
> v1-v3:
> - patch not present
> ---
> kernel/sysctl.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index c4a44b7ccb8a..516bc8a2812d 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -2846,8 +2846,10 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
> if (neg)
> continue;
> val = convmul * val / convdiv;
> - if ((min && val < *min) || (max && val > *max))
> - continue;
> + if ((min && val < *min) || (max && val > *max)) {
> + err = -EINVAL;
> + break;
> + }
> *i = val;
> } else {
> val = convdiv * (*i) / convmul;
> --
> 2.20.1
>
prev parent reply other threads:[~2019-02-11 19:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-10 20:39 [PATCH v4 0/3] sysctl: handle overflow for file-max Christian Brauner
2019-02-10 20:39 ` [PATCH v4 1/3] sysctl: handle overflow in proc_get_long Christian Brauner
2019-02-10 20:39 ` [PATCH v4 2/3] sysctl: handle overflow for file-max Christian Brauner
2019-02-10 20:39 ` [RFC PATCH v4 3/3] sysctl: return -EINVAL if val violates minmax Christian Brauner
2019-02-11 19:50 ` Luis Chamberlain [this message]
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=20190211195025.GT11489@garbanzo.do-not-panic.com \
--to=mcgrof@kernel.org \
--cc=adobriyan@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=christian@brauner.io \
--cc=ebiederm@xmission.com \
--cc=joe.lawrence@redhat.com \
--cc=keescook@chromium.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@dominikbrodowski.net \
--cc=longman@redhat.com \
--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).