linux-hardening - Re: [PATCH v2] scsi: target: Replace deprecated strncpy() with strscpy()

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: <202503031045.1E2D5BE@keescook>
Date: Mon, 3 Mar 2025 10:45:48 -0800
From: Kees Cook <kees@...nel.org>
To: Thorsten Blum <thorsten.blum@...ux.dev>
Cc: "Martin K. Petersen" <martin.petersen@...cle.com>,
	linux-hardening@...r.kernel.org, linux-scsi@...r.kernel.org,
	target-devel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] scsi: target: Replace deprecated strncpy() with
 strscpy()

On Sun, Mar 02, 2025 at 11:56:41PM +0100, Thorsten Blum wrote:
> strncpy() is deprecated for NUL-terminated destination buffers; use
> strscpy() instead. The destination buffer db_root is only used with "%s"
> format strings and must therefore be NUL-terminated, but not NUL-padded.
> 
> Use scnprintf() because snprintf() could return a value >= DB_ROOT_LEN
> and lead to an out-of-bounds access. This doesn't happen because count
> is explicitly checked against DB_ROOT_LEN before. However, scnprintf()
> always returns the number of characters actually written to the string
> buffer, which is always within the bounds of db_root_stage, and should
> be preferred over snprintf().
> 
> The size parameter of strscpy() is optional and since DB_ROOT_LEN is the
> size of the destination buffer, it can be removed. Remove it to simplify
> the code.
> 
> Compile-tested only.
> 
> Link: https://github.com/KSPP/linux/issues/90
> Link: https://github.com/KSPP/linux/issues/105
> Cc: linux-hardening@...r.kernel.org
> Signed-off-by: Thorsten Blum <thorsten.blum@...ux.dev>

Reviewed-by: Kees Cook <kees@...nel.org>

-- 
Kees Cook