linux-kernel - Re: [PATCH] thinkpad_acpi: fix: use scnprintf instead of snprintf.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2d5f6ffcf47ec4675cde21ff52fc70a9dd13b023.camel@perches.com>
Date:   Wed, 06 Jan 2021 01:01:37 -0800
From:   Joe Perches <joe@...ches.com>
To:     YANG LI <abaci-bugfix@...ux.alibaba.com>, hdegoede@...hat.com
Cc:     mgross@...ux.intel.com, ibm-acpi@....eng.br,
        ibm-acpi-devel@...ts.sourceforge.net,
        platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] thinkpad_acpi: fix: use scnprintf instead of snprintf.

On Wed, 2021-01-06 at 14:36 +0800, YANG LI wrote:
> The snprintf() function returns the number of characters which would
> have been printed if there were enough space, but the scnprintf()
> returns the number of characters which were actually printed. If the
> buffer is not large enough, then using snprintf() would result in a
> read overflow and an information leak. This error was found with the
> help of coccicheck.

In all cases, the buffer _is_ large enough.

tmpi is length 5 and ok.
include/sound/core.h:   char shortname[32];             /* short name of this soundcard */
include/sound/core.h:   char longname[80];              /* name of this soundcard */
include/sound/core.h:   char mixername[80];             /* mixer name */

_show function lengths are OK for all the uses with PAGE_SIZE.
And it's probably better to use sysfs_emit for all the _show functions