linux-kernel - Re: [PATCH] CIFS: Fix a potencially linear read overflow

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]

Date:   Tue, 17 Aug 2021 21:28:40 -0300
From:   Paulo Alcantara <pc@....nz>
To:     Len Baker <len.baker@....com>, Steve French <sfrench@...ba.org>,
        Jeff Layton <jlayton@...nel.org>,
        Suresh Jayaraman <sjayaraman@...e.de>
Cc:     Len Baker <len.baker@....com>, linux-cifs@...r.kernel.org,
        samba-technical@...ts.samba.org, linux-kernel@...r.kernel.org,
        Kees Cook <keescook@...omium.org>,
        linux-hardening@...r.kernel.org
Subject: Re: [PATCH] CIFS: Fix a potencially linear read overflow

Len Baker <len.baker@....com> writes:

> strlcpy() reads the entire source buffer first. This read may exceed the
> destination size limit. This is both inefficient and can lead to linear
> read overflows if a source string is not NUL-terminated.
>
> Also, the strnlen() call does not avoid the read overflow in the strlcpy
> function when a not NUL-terminated string is passed.
>
> So, replace this block by a call to kstrndup() that avoids this type of
> overflow and does the same.
>
> Fixes: 066ce6899484d ("cifs: rename cifs_strlcpy_to_host and make it use new functions")
> Signed-off-by: Len Baker <len.baker@....com>
> ---
>  fs/cifs/cifs_unicode.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)

Reviewed-by: Paulo Alcantara (SUSE) <pc@....nz>