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>

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>
Sasha Levin · David S. Miller · Eric Lee · Eric Lee · Eric Lee · Eric Lee
1 parent fcdfe3a7fa
Showing 1 changed file with 4 additions and 0 deletions Side-by-side Diff
lib/iovec.c
@@ -85,6 +85,10 @@
 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;
...	...	@@ -85,6 +85,10 @@
85	85	int memcpy_fromiovecend(unsigned char kdata, const struct iovec iov,
86	86	int offset, int len)
87	87	{
	88	+ /* No data? Done! */
	89	+ if (len == 0)
	90	+ return 0;
	91	+
88	92	/* Skip over the finished iovecs */
89	93	while (offset >= iov->iov_len) {
90	94	offset -= iov->iov_len;