From: David Ahern <dsahern@gmail.com>
Date: Thu, 1 Mar 2018 22:43:08 +0000 (-0800)
Subject: libnetlink: __rtnl_talk_iov should only loop max iovlen times
X-Git-Tag: v4.16.0~36
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3dec72672f7b293ad773568c2c4a0d11fa8c4529;p=thirdparty%2Fiproute2.git

libnetlink: __rtnl_talk_iov should only loop max iovlen times

William reported ip hanging and bisected to a recent commit for batching
allowing more than 1 command to be sent per message. The loop over
recvmsg should never cycle more than iovlen times -- 1 response for
each command in the message.

Fixes: 72a2ff3916e5 ("lib/libnetlink: Add a new function rtnl_talk_iov")
Signed-off-by: David Ahern <dsahern@gmail.com>
---

diff --git a/lib/libnetlink.c b/lib/libnetlink.c
index 8bb1c8d7d..928de1dd1 100644
--- a/lib/libnetlink.c
+++ b/lib/libnetlink.c
@@ -670,8 +670,9 @@ next:
 						free(buf);
 					if (h->nlmsg_seq == seq)
 						return 0;
-					else
+					else if (i < iovlen)
 						goto next;
+					return 0;
 				}
 
 				if (rtnl->proto != NETLINK_SOCK_DIAG &&