virtiofsd: Fix security.capability comparison

My security fix for the security.capability remap has a silly early
segfault in a simple case where there is an xattrmapping but it doesn't
remap the security.capability.

Fixes: e586edcb41054 ("virtiofs: drop remapped security.capability xattr as needed")
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20210401145845.78445-1-dgilbert@redhat.com>
Reviewed-by: Connor Kuehl <ckuehl@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index b144320e48968aae414789d2f380f42d262a24e0..1553d2ef454f55a3103b452841d51215e9ecfc2b 100644 (file)
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -2636,7 +2636,8 @@ static void parse_xattrmap(struct lo_data *lo)
                 strerror(ret));
         exit(1);
     }
-    if (!strcmp(lo->xattr_security_capability, "security.capability")) {
+    if (!lo->xattr_security_capability ||
+        !strcmp(lo->xattr_security_capability, "security.capability")) {
         /* 1-1 mapping, don't need to do anything */
         free(lo->xattr_security_capability);
         lo->xattr_security_capability = NULL;