[master] 4e4d66b33 acceptor: Address false positive in Coverity Scan

[Dridi Boukelmoune]

commit 4e4d66b33ee79217808936f9b6d0796456e2ab7f
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Mon Dec 5 11:26:51 2022 +0100

    acceptor: Address false positive in Coverity Scan
    
    Upon success we expect a non-null pointer, and to make sure this is not
    residual uninitialized stack memory, it is null'd beforehand.
    
        /bin/varnishd/cache/cache_acceptor.c: 375 in vca_mk_tcp()
        369     {
        370             struct suckaddr *sa;
        371             ssize_t sz;
        372
        373             AN(SES_Reserve_remote_addr(sp, &sa, &sz));
        374             assert(sz == vsa_suckaddr_len);
        >>>     CID 1517259:  Resource leaks  (RESOURCE_LEAK)
        >>>     Failing to save or free storage allocated by "VSA_Build(sa, &wa->acceptaddr, wa->acceptaddrlen)" leaks it.
        375             AN(VSA_Build(sa, &wa->acceptaddr, wa->acceptaddrlen));
        376             sp->sattr[SA_CLIENT_ADDR] = sp->sattr[SA_REMOTE_ADDR];
    
    It is precisely because we reserve the space to store the built suckaddr
    that there won't be a malloc() call made behind our back.
    
    For some reason, it only complained about one call site.

diff --git a/bin/varnishd/cache/cache_acceptor.c b/bin/varnishd/cache/cache_acceptor.c
index 67947114b..b25e186f0 100644
--- a/bin/varnishd/cache/cache_acceptor.c
+++ b/bin/varnishd/cache/cache_acceptor.c
@@ -367,10 +367,11 @@ static void
 vca_mk_tcp(const struct wrk_accept *wa,
     struct sess *sp, char *laddr, char *lport, char *raddr, char *rport)
 {
-	struct suckaddr *sa;
+	struct suckaddr *sa = NULL;
 	ssize_t sz;
 
 	AN(SES_Reserve_remote_addr(sp, &sa, &sz));
+	AN(sa);
 	assert(sz == vsa_suckaddr_len);
 	AN(VSA_Build(sa, &wa->acceptaddr, wa->acceptaddrlen));
 	sp->sattr[SA_CLIENT_ADDR] = sp->sattr[SA_REMOTE_ADDR];
@@ -390,11 +391,12 @@ static void
 vca_mk_uds(struct wrk_accept *wa, struct sess *sp, char *laddr, char *lport,
 	   char *raddr, char *rport)
 {
-	struct suckaddr *sa;
+	struct suckaddr *sa = NULL;
 	ssize_t sz;
 
 	(void) wa;
 	AN(SES_Reserve_remote_addr(sp, &sa, &sz));
+	AN(sa);
 	assert(sz == vsa_suckaddr_len);
 	AZ(SES_Set_remote_addr(sp, bogo_ip));
 	sp->sattr[SA_CLIENT_ADDR] = sp->sattr[SA_REMOTE_ADDR];