From 06ebb06d49486676272a3c030bfeef4bd969a8e6 Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Thu, 31 Jul 2014 23:00:35 -0400 Subject: [PATCH] iovec: make sure the caller actually wants anything in memcpy_fromiovecend Check for cases when the caller requests 0 bytes instead of running off and dereferencing potentially invalid iovecs. Signed-off-by: Sasha Levin Signed-off-by: David S. Miller --- lib/iovec.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/iovec.c b/lib/iovec.c index 7a7c2da..df3abd1 100644 --- a/lib/iovec.c +++ b/lib/iovec.c @@ -85,6 +85,10 @@ EXPORT_SYMBOL(memcpy_toiovecend); int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov, int offset, int len) { + /* No data? Done! */ + if (len == 0) + return 0; + /* Skip over the finished iovecs */ while (offset >= iov->iov_len) { offset -= iov->iov_len; -- 2.7.4