From: Clemens Ladisch <clemens@ladisch.de>
Date: Wed, 31 Mar 2010 14:26:39 +0000 (+0200)
Subject: firewire: cdev: disallow receive packets without header
X-Git-Tag: firefly_0821_release~9833^2~1655^2~17
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=4ba1d9c0c22947a9207029e7184733252e6135f1;p=firefly-linux-kernel-4.4.55.git

firewire: cdev: disallow receive packets without header

In receive contexts, reject packets with header_length==0.  This would
be an instruction to queue zero packets which would not make sense.

This prevents a division by zero in the OHCI driver.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
---

diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 8be720b278b7..bbb8160e2c99 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -968,7 +968,8 @@ static int ioctl_queue_iso(struct client *client, union ioctl_arg *arg)
 			if (ctx->header_size == 0) {
 				if (u.packet.header_length > 0)
 					return -EINVAL;
-			} else if (u.packet.header_length % ctx->header_size != 0) {
+			} else if (u.packet.header_length == 0 ||
+				   u.packet.header_length % ctx->header_size != 0) {
 				return -EINVAL;
 			}
 			header_length = 0;