From: Alexander Aring aahringo@redhat.com
[ 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 --- fs/dlm/midcomms.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/fs/dlm/midcomms.c b/fs/dlm/midcomms.c index fde3a6afe4be..0bedfa8606a2 100644 --- a/fs/dlm/midcomms.c +++ b/fs/dlm/midcomms.c @@ -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; }