From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37656) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bnIlI-0001Xt-Dk for qemu-devel@nongnu.org; Fri, 23 Sep 2016 01:11:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bnIlG-0007MK-F0 for qemu-devel@nongnu.org; Fri, 23 Sep 2016 01:10:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39904) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bnIlG-0007MG-9U for qemu-devel@nongnu.org; Fri, 23 Sep 2016 01:10:58 -0400 From: Fam Zheng Date: Fri, 23 Sep 2016 13:10:18 +0800 Message-Id: <1474607430-26500-12-git-send-email-famz@redhat.com> In-Reply-To: <1474607430-26500-1-git-send-email-famz@redhat.com> References: <1474607430-26500-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [PULL 11/23] uuid: Tighten uuid parse List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell sscanf is relatively loose (tolerate) on some invalid formats that we should fail instead of generating a wrong uuid structure, like with whitespaces and short strings. Add and use a helper function to first check the format. Signed-off-by: Fam Zheng Reviewed-by: Eric Blake Reviewed-by: Jeff Cody Message-Id: <1474432046-325-11-git-send-email-famz@redhat.com> --- util/uuid.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/util/uuid.c b/util/uuid.c index 4701903..dd6b5fd 100644 --- a/util/uuid.c +++ b/util/uuid.c @@ -61,12 +61,34 @@ char *qemu_uuid_unparse_strdup(const QemuUUID *uuid) uu[13], uu[14], uu[15]); } +static bool qemu_uuid_is_valid(const char *str) +{ + int i; + + for (i = 0; i < strlen(str); i++) { + const char c = str[i]; + if (i == 8 || i == 13 || i == 18 || i == 23) { + if (str[i] != '-') { + return false; + } + } else { + if ((c >= '0' && c <= '9') || + (c >= 'A' && c <= 'F') || + (c >= 'a' && c <= 'f')) { + continue; + } + return false; + } + } + return i == 36; +} + int qemu_uuid_parse(const char *str, QemuUUID *uuid) { unsigned char *uu = &uuid->data[0]; int ret; - if (strlen(str) != 36) { + if (!qemu_uuid_is_valid(str)) { return -1; } -- 2.7.4