Patch "aacraid: Check size values after double-fetch from user" has been added to the 4.7-stable tree

This is a note to let you know that I've just added the patch titled

aacraid: Check size values after double-fetch from user

to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
aacraid-check-size-values-after-double-fetch-from-user.patch
and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Dave Carroll <[email protected]>
Date: Fri, 5 Aug 2016 13:44:10 -0600
Subject: aacraid: Check size values after double-fetch from user

From: Dave Carroll <[email protected]>

commit fa00c437eef8dc2e7b25f8cd868cfa405fcc2bb3 upstream.

In aacraid's ioctl_send_fib() we do two fetches from userspace, one the get the fib header's size and one for the fib itself. Later we use the size field from the second fetch to further process the fib. If for some reason the size from the second fetch is different than from the first fix, we may encounter an out-of- bounds access in aac_fib_send(). We also check the sender size to insure it is not out of bounds. This was reported in https://bugzilla.kernel.org/show_bug.cgi?id=116751 and was assigned CVE-2016-6480.

---
 drivers/scsi/aacraid/commctrl.c |   13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

@@ -63,7 +63,7 @@ static int ioctl_send_fib(struct aac_dev
 	struct fib *fibptr;
 	struct hw_fib * hw_fib = (struct hw_fib *)0;
 	dma_addr_t hw_fib_pa = (dma_addr_t)0LL;
-	unsigned size;
+	unsigned int size, osize;
 	int retval;
 
 	if (dev->in_reset) {

@@ -87,7 +87,8 @@ static int ioctl_send_fib(struct aac_dev
 	 *	will not overrun the buffer when we copy the memory. Return
 	 *	an error if we would.
 	 */
-	size = le16_to_cpu(kfib->header.Size) + sizeof(struct aac_fibhdr);
+	osize = size = le16_to_cpu(kfib->header.Size) +
+		sizeof(struct aac_fibhdr);
 	if (size < le16_to_cpu(kfib->header.SenderSize))
 		size = le16_to_cpu(kfib->header.SenderSize);
 	if (size > dev->max_fib_size) {

@@ -118,6 +119,14 @@ static int ioctl_send_fib(struct aac_dev
 		goto cleanup;
 	}
 
+	/* Sanity check the second copy */
+	if ((osize != le16_to_cpu(kfib->header.Size) +
+		sizeof(struct aac_fibhdr))
+		|| (size < le16_to_cpu(kfib->header.SenderSize))) {
+		retval = -EINVAL;
+		goto cleanup;
+	}
+
 	if (kfib->header.Command == cpu_to_le16(TakeABreakPt)) {
 		aac_adapter_interrupt(dev);
 		/*

Patches currently in stable-queue which might be from [email protected] are

queue-4.7/aacraid-check-size-values-after-double-fetch-from-user.patch