Patch "infiniband/uverbs: Fix integer overflows" has been added to the 4.4-stable tree

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

infiniband/uverbs: Fix integer overflows

to the 4.4-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:
infiniband-uverbs-fix-integer-overflows.patch
and it can be found in the queue-4.4 subdirectory.

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

From: Vlad Tsyrklevich <[email protected]>
Date: Fri, 24 Mar 2017 15:55:17 -0400
Subject: infiniband/uverbs: Fix integer overflows

From: Vlad Tsyrklevich <[email protected]>

[ Upstream commit 4f7f4dcfff2c19debbcdbcc861c325610a15e0c5 ]

The 'num_sge' variable is verfied to be smaller than the 'sge_count' variable; however, since both are user-controlled it's possible to cause an integer overflow for the kmalloc multiply on 32-bit platforms (num_sge and sge_count are both defined u32). By crafting an input that causes a smaller-than-expected allocation it's possible to write controlled data out-of-bounds.

---
 drivers/infiniband/core/uverbs_cmd.c |   13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

@@ -2436,9 +2436,13 @@ ssize_t ib_uverbs_destroy_qp(struct ib_u
 
 static void *alloc_wr(size_t wr_size, __u32 num_sge)
 {
+	if (num_sge >= (U32_MAX - ALIGN(wr_size, sizeof (struct ib_sge))) /
+		       sizeof (struct ib_sge))
+		return NULL;
+
 	return kmalloc(ALIGN(wr_size, sizeof (struct ib_sge)) +
 			 num_sge * sizeof (struct ib_sge), GFP_KERNEL);
-};
+}
 
 ssize_t ib_uverbs_post_send(struct ib_uverbs_file *file,
 			    struct ib_device *ib_dev,

@@ -2664,6 +2668,13 @@ static struct ib_recv_wr *ib_uverbs_unma
 			ret = -EINVAL;
 			goto err;
 		}
+
+		if (user_wr->num_sge >=
+		    (U32_MAX - ALIGN(sizeof *next, sizeof (struct ib_sge))) /
+		    sizeof (struct ib_sge)) {
+			ret = -EINVAL;
+			goto err;
+		}
 
 		next = kmalloc(ALIGN(sizeof *next, sizeof (struct ib_sge)) +
 			       user_wr->num_sge * sizeof (struct ib_sge),

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

queue-4.4/infiniband-uverbs-fix-integer-overflows.patch