Commit 99c3ac6dbe for qemu.org

commit 99c3ac6dbe18cdab3686a830d129f8fa586846bb
Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
Date:   Thu Apr 1 15:58:45 2021 +0100

    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 b144320e48..1553d2ef45 100644
--- 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;