[4.1] 26d5261 Fix memory leak of vary string on stevedore alloc fail

[PÃ¥l Hermunn Johansen]

commit 26d52615004730eb28ce603930600d44cafd8202
Author: Martin Blix Grydeland <martin at varnish-software.com>
Date:   Wed Mar 14 13:52:36 2018 +0100

    Fix memory leak of vary string on stevedore alloc fail
    
    If the stevedore failed the object creation, we would leak the temporary
    VSB holding the computed vary string. This patch frees it.
    
    Problem exists in 4.1 and later.

diff --git a/bin/varnishd/cache/cache_fetch.c b/bin/varnishd/cache/cache_fetch.c
index b356828..902ad17 100644
--- a/bin/varnishd/cache/cache_fetch.c
+++ b/bin/varnishd/cache/cache_fetch.c
@@ -125,8 +125,12 @@ vbf_beresp2obj(struct busyobj *bo)
 	if (bo->uncacheable)
 		bo->fetch_objcore->flags |= OC_F_PASS;
 
-	if (!vbf_allocobj(bo, l))
+	if (!vbf_allocobj(bo, l)) {
+		if (vary != NULL)
+			VSB_destroy(&vary);
+		AZ(vary);
 		return (-1);
+	}
 
 	if (vary != NULL) {
 		b = ObjSetattr(bo->wrk, bo->fetch_objcore, OA_VARY, varyl,