From 81278fd6c82c8a1c22c65f1ae1ea048d2473dbfe Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Tue, 8 Sep 2015 18:06:24 +0200 Subject: [PATCH 6/7] util/uri: URI member path can be null, compare more carfully Message-id: <1441735585-23432-7-git-send-email-armbru@redhat.com> Patchwork-id: 67709 O-Subject: [RHEL-7.2 qemu-kvm PATCH 6/7] util/uri: URI member path can be null, compare more carfully Bugzilla: 1218919 RH-Acked-by: Laszlo Ersek RH-Acked-by: Fam Zheng RH-Acked-by: Dr. David Alan Gilbert uri_resolve_relative() calls strcmp(bas->path, ref->path). However, either argument could be null! Evidence: the code checks for null after the comparison. Spotted by Coverity. I suspect this was screwed up when we stole the code from libxml2. There the conditional reads xmlStrEqual((xmlChar *)bas->path, (xmlChar *)ref->path) with int xmlStrEqual(const xmlChar *str1, const xmlChar *str2) { if (str1 == str2) return(1); if (str1 == NULL) return(0); if (str2 == NULL) return(0); do { if (*str1++ != *str2) return(0); } while (*str2++); return(1); } Fix by replicating libxml2's logic faithfully. Cc: Paolo Bonzini Signed-off-by: Markus Armbruster Signed-off-by: Michael Tokarev (cherry picked from commit afb30dde3ad71349fc65726946d58e5d3c61f8af) Signed-off-by: Miroslav Rezanina --- util/uri.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/util/uri.c b/util/uri.c index b9a7b54..1cfd78b 100644 --- a/util/uri.c +++ b/util/uri.c @@ -1935,7 +1935,8 @@ uri_resolve_relative (const char *uri, const char * base) val = g_strdup (uri); goto done; } - if (!strcmp(bas->path, ref->path)) { + if (bas->path == ref->path || + (bas->path && ref->path && !strcmp(bas->path, ref->path))) { val = g_strdup(""); goto done; } -- 1.8.3.1