From: Mohamed Ghannam <simo.ghannam@gmail.com>
Date: Tue, 2 Jan 2018 19:44:34 +0000 (+0000)
Subject: RDS: Heap OOB write in rds_message_alloc_sgs()
X-Git-Tag: v4.4.112~43
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=10d06ed9a1899fcc1ecb7a1573f0f95b92dc470c;p=thirdparty%2Fkernel%2Fstable.git

RDS: Heap OOB write in rds_message_alloc_sgs()


[ Upstream commit c095508770aebf1b9218e77026e48345d719b17c ]

When args->nr_local is 0, nr_pages gets also 0 due some size
calculation via rds_rm_size(), which is later used to allocate
pages for DMA, this bug produces a heap Out-Of-Bound write access
to a specific memory region.

Signed-off-by: Mohamed Ghannam <simo.ghannam@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index bdf151c6307dc..f96f124bc21cd 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -517,6 +517,9 @@ int rds_rdma_extra_size(struct rds_rdma_args *args)
 
 	local_vec = (struct rds_iovec __user *)(unsigned long) args->local_vec_addr;
 
+	if (args->nr_local == 0)
+		return -EINVAL;
+
 	/* figure out the number of pages in the vector */
 	for (i = 0; i < args->nr_local; i++) {
 		if (copy_from_user(&vec, &local_vec[i],