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
| ||
|
Message-ID: <202310241027.516C46AA@keescook> Date: Tue, 24 Oct 2023 10:28:48 -0700 From: Kees Cook <keescook@...omium.org> To: Justin Stitt <justinstitt@...gle.com> Cc: Alexandra Winter <wintera@...ux.ibm.com>, Wenjia Zhang <wenjia@...ux.ibm.com>, Heiko Carstens <hca@...ux.ibm.com>, Vasily Gorbik <gor@...ux.ibm.com>, Alexander Gordeev <agordeev@...ux.ibm.com>, Christian Borntraeger <borntraeger@...ux.ibm.com>, Sven Schnelle <svens@...ux.ibm.com>, linux-s390@...r.kernel.org, netdev@...r.kernel.org, linux-kernel@...r.kernel.org, linux-hardening@...r.kernel.org Subject: Re: [PATCH] s390/ctcm: replace deprecated strncpy with strscpy On Mon, Oct 23, 2023 at 07:35:07PM +0000, Justin Stitt wrote: > strncpy() is deprecated for use on NUL-terminated destination strings > [1] and as such we should prefer more robust and less ambiguous string > interfaces. > > We expect chid to be NUL-terminated based on its use with format > strings: > > CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO, "%s(%s) %s", CTCM_FUNTAIL, > chid, ok ? "OK" : "failed"); > > Moreover, NUL-padding is not required as it is _only_ used in this one > instance with a format string. > > Considering the above, a suitable replacement is `strscpy` [2] due to > the fact that it guarantees NUL-termination on the destination buffer > without unnecessarily NUL-padding. > > We can also drop the +1 from chid's declaration as we no longer need to > be cautious about leaving a spot for a NUL-byte. Let's use the more > idiomatic strscpy usage of (dest, src, sizeof(dest)) as this more > closely ties the destination buffer to the length. > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@...r.kernel.org > Signed-off-by: Justin Stitt <justinstitt@...gle.com> Yeah, all looks correct to me. Reviewed-by: Kees Cook <keescook@...omium.org> -- Kees Cook
Powered by blists - more mailing lists