From: Dan Rosenberg <drosenberg@vsecurity.com>
Date: Wed, 17 Nov 2010 06:37:16 +0000 (+0000)
Subject: rds: Integer overflow in RDS cmsg handling
X-Git-Tag: firefly_0821_release~10186^2~631
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0dd472b3a508ae8ec0b7ff3396e1a17434b78a75;p=firefly-linux-kernel-4.4.55.git

rds: Integer overflow in RDS cmsg handling

commit 218854af84038d828a32f061858b1902ed2beec6 upstream.

In rds_cmsg_rdma_args(), the user-provided args->nr_local value is
restricted to less than UINT_MAX.  This seems to need a tighter upper
bound, since the calculation of total iov_size can overflow, resulting
in a small sock_kmalloc() allocation.  This would probably just result
in walking off the heap and crashing when calling rds_rdma_pages() with
a high count value.  If it somehow doesn't crash here, then memory
corruption could occur soon after.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index 8dc83d2caa58..6b09b941d3a7 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -447,7 +447,7 @@ static struct rds_rdma_op *rds_rdma_prepare(struct rds_sock *rs,
 		goto out;
 	}
 
-	if (args->nr_local > (u64)UINT_MAX) {
+	if (args->nr_local > UIO_MAXIOV) {
 		ret = -EMSGSIZE;
 		goto out;
 	}