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 <sasha.levin@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Sasha Levin 2014-07-31 23:00:35 -04:00 committed by David S. Miller
parent fcdfe3a7fa
commit 06ebb06d49

View File

@ -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;