From: Willy Tarreau <w@1wt.eu>
Date: Thu, 20 Sep 2018 09:39:39 +0000 (+0200)
Subject: BUILD: sockpair: silence a build warning at -Wextra
X-Git-Tag: v1.9-dev3~10
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7d7ab43a33f86e39fa3ce232e84235c9ed590445;p=thirdparty%2Fhaproxy.git

BUILD: sockpair: silence a build warning at -Wextra

An invalid null-deref warning is emitted because cmsg is not checked,
though it definitely is valid given the test performed 10 lines above,
but the compiler cannot necessarily guess this. Adding a null test to
the problematic condition is enough to get rid of it and cheap enough.
---

diff --git a/src/proto_sockpair.c b/src/proto_sockpair.c
index 8f4a87462e..bc8557a0d0 100644
--- a/src/proto_sockpair.c
+++ b/src/proto_sockpair.c
@@ -382,7 +382,7 @@ int recv_fd_uxst(int sock)
 		return ret;
 
 	cmsg = CMSG_FIRSTHDR(&msghdr);
-	if (cmsg->cmsg_level == SOL_SOCKET &&
+	if (cmsg && cmsg->cmsg_level == SOL_SOCKET &&
 	    cmsg->cmsg_type == SCM_RIGHTS) {
 		size_t totlen = cmsg->cmsg_len -
 			CMSG_LEN(0);