iovec: make sure the caller actually wants anything in memcpy_fromiovecend

[ Upstream commit 06ebb06d49 ]

Check for cases when the caller requests 0 bytes instead of running off
and dereferencing potentially invalid iovecs.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sasha Levin 2014-07-31 23:00:35 -04:00 committed by Greg Kroah-Hartman
parent 80db1671bd
commit 8fbbef088e

View file

@ -157,6 +157,10 @@ EXPORT_SYMBOL(memcpy_fromiovec);
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;