From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43893) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ukf3g-00035m-L9 for qemu-devel@nongnu.org; Thu, 06 Jun 2013 14:37:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ukf3Z-0003WL-NL for qemu-devel@nongnu.org; Thu, 06 Jun 2013 14:37:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38418) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ukf3Z-0003Vq-E8 for qemu-devel@nongnu.org; Thu, 06 Jun 2013 14:37:05 -0400 Message-ID: <51B0D75E.8000305@redhat.com> Date: Thu, 06 Jun 2013 20:39:26 +0200 From: Laszlo Ersek MIME-Version: 1.0 References: <1370536046-15125-1-git-send-email-armbru@redhat.com> <1370536046-15125-8-git-send-email-armbru@redhat.com> In-Reply-To: <1370536046-15125-8-git-send-email-armbru@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 7/7] smbios: Check R in -smbios type=0, release=R parses okay List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: aliguori@us.ibm.com, qemu-devel@nongnu.org On 06/06/13 18:27, Markus Armbruster wrote: > Signed-off-by: Markus Armbruster > --- > hw/i386/smbios.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/hw/i386/smbios.c b/hw/i386/smbios.c > index 68bd6d0..88a1360 100644 > --- a/hw/i386/smbios.c > +++ b/hw/i386/smbios.c > @@ -140,7 +140,10 @@ static void smbios_build_type_0_fields(const char *t) > bios_release_date_str), > buf, strlen(buf) + 1); > if (get_param_value(buf, sizeof(buf), "release", t)) { > - sscanf(buf, "%hhd.%hhd", &major, &minor); > + if (sscanf(buf, "%hhd.%hhd", &major, &minor) != 2) { > + error_report("Invalid release"); > + exit(1); > + } > smbios_add_field(0, offsetof(struct smbios_type_0, > system_bios_major_release), > &major, 1); > Right. OTOH if any of the decimal strings provided doesn't fit into the space provided (eg. you pass "256" for an "unsigned char" which happens to be uint8_t), the behavior is undefined anyway. sscanf() cannot be used with "untrusted" data. ("... if the result of the conversion cannot be represented in the space provided, the behavior is undefined.") Reviewed-by: Laszlo Ersek