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-Url: http://rtime.felk.cvut.cz/gitweb/lisovros/linux_canprio.git/commitdiff_plain/df76d4ac11f3b4e718e0737e2b5f7972948ca805?hp=a072d3e9840e924180044f9b68041b5c338a812b

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 75fd13bb631..39989678c2d 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -474,7 +474,7 @@ 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;
 	}