commit eef708830868da75526d9eb3bfac87488ed93933
author Paul Lawrence <paullawrence@google.com> Wed Oct 18 09:20:15 2017 -0700
committer Masakazu Yamazaki <yamazaki-m@casio.co.jp> Tue Feb 20 11:53:41 2018 +0900
tree 2083a6feba6f9357961d041bb505fb7fb1061e71
parent 039b6047b4719a18be40edf2126777eed20ae161

iovec: make sure the caller actually wants anything in memcpy_fromiovecend

Based on upstream change 06ebb06d49486676272a3c030bfeef4bd969a8e6

One more instance when the caller requests 0 bytes instead of running
off and dereferencing potentially invalid iovecs.

Signed-off-by: Paul Lawrence <paullawrence@google.com>
Bug: 36279469
Change-Id: Ib8d529e17c07c77357ab70bd6a2d7e305d6b27f0

net/core/iovec.c

diff --git a/net/core/iovec.c b/net/core/iovec.c
index e1ec45a..4c3fd58 100644
--- a/net/core/iovec.c
+++ b/net/core/iovec.c
@@ -88,6 +88,10 @@
 	__wsum csum = *csump;
 	int partial_cnt = 0, err = 0;
 
+	/* No data? Done! */
+	if (len == 0)
+		return 0;
+
 	/* Skip over the finished iovecs */
 	while (offset >= iov->iov_len) {
 		offset -= iov->iov_len;