Tools: hv: correct payload size in netlink_send

netlink_send is supposed to send just the cn_msg+hv_kvp_msg via netlink.
Currently it sets an incorrect iovec size, as reported by valgrind.

In the case of registering with the kernel the allocated buffer is large
enough to hold nlmsghdr+cn_msg+hv_kvp_msg, no overrun happens. In the
case of responding to the kernel the cn_msg is located in the middle of
recv_buffer, after the nlmsghdr. Currently the code in netlink_send adds
also the size of nlmsghdr to the payload. But nlmsghdr is a separate
iovec. This leads to an (harmless) out-of-bounds access when the kernel
processes the iovec. Correct the iovec size of the cn_msg to be just
cn_msg + its payload.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Olaf Hering 2013-08-07 15:07:21 +02:00 committed by Greg Kroah-Hartman
parent d3b688c662
commit 2bc41ea3b3
2 changed files with 2 additions and 2 deletions

View File

@ -1398,7 +1398,7 @@ netlink_send(int fd, struct cn_msg *msg)
char buffer[64];
struct iovec iov[2];
size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len);
size = sizeof(struct cn_msg) + msg->len;
nlh = (struct nlmsghdr *)buffer;
nlh->nlmsg_seq = 0;

View File

@ -111,7 +111,7 @@ static int netlink_send(int fd, struct cn_msg *msg)
char buffer[64];
struct iovec iov[2];
size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len);
size = sizeof(struct cn_msg) + msg->len;
nlh = (struct nlmsghdr *)buffer;
nlh->nlmsg_seq = 0;