fs: dlm: check on minimum msglen size

[ Upstream commit 710176e8363f269c6ecd73d203973b31ace119d3 ]

This patch adds an additional check for minimum dlm header size which is
an invalid dlm message and signals a broken stream. A msglen field cannot
be less than the dlm header size because the field is inclusive header
lengths.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Alexander Aring 2021-03-01 17:05:17 -05:00 committed by Greg Kroah-Hartman
parent ca973d2aea
commit ff58d1c72e

View File

@ -49,9 +49,10 @@ int dlm_process_incoming_buffer(int nodeid, unsigned char *buf, int len)
* cannot deliver this message to upper layers
*/
msglen = get_unaligned_le16(&hd->h_length);
if (msglen > DEFAULT_BUFFER_SIZE) {
log_print("received invalid length header: %u, will abort message parsing",
msglen);
if (msglen > DEFAULT_BUFFER_SIZE ||
msglen < sizeof(struct dlm_header)) {
log_print("received invalid length header: %u from node %d, will abort message parsing",
msglen, nodeid);
return -EBADMSG;
}