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: <202310241658.0144D73@keescook> Date: Tue, 24 Oct 2023 16:58:50 -0700 From: Kees Cook <keescook@...omium.org> To: Justin Stitt <justinstitt@...gle.com> Cc: Vineeth Vijayan <vneethv@...ux.ibm.com>, Peter Oberparleiter <oberpar@...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, linux-kernel@...r.kernel.org, linux-hardening@...r.kernel.org Subject: Re: [PATCH] s390/cio: replace deprecated strncpy with strscpy On Mon, Oct 23, 2023 at 07:24:38PM +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 both `params` and `id` to be NUL-terminated based on their > usage with format strings: > > format_node_data(iuparams, iunodeid, &lir->incident_node); > format_node_data(auparams, aunodeid, &lir->attached_node); > > switch (lir->iq.class) { > case LIR_IQ_CLASS_DEGRADED: > pr_warn("Link degraded: RS=%02x RSID=%04x IC=%02x " > "IUPARAMS=%s IUNODEID=%s AUPARAMS=%s AUNODEID=%s\n", > sei_area->rs, sei_area->rsid, lir->ic, iuparams, > iunodeid, auparams, aunodeid); > > NUL-padding is not required as both `params` and `id` have been memset > to 0: > > memset(params, 0, PARAMS_LEN); > memset(id, 0, NODEID_LEN); > > 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. > > Note that there's no overread bugs in the current implementation as the > string literal "n/a" has a size much smaller than PARAMS_LEN or > NODEID_LEN. Nonetheless, let's favor strscpy(). > > 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> Looks good. Reviewed-by: Kees Cook <keescook@...omium.org> -- Kees Cook
Powered by blists - more mailing lists