From: Mohamed Ghannam <simo.ghannam@gmail.com>
Date: Tue, 2 Jan 2018 19:44:34 +0000
Subject: RDS: Heap OOB write in rds_message_alloc_sgs()
Patch-mainline: v4.15-rc8
Git-commit: c095508770aebf1b9218e77026e48345d719b17c
References: CVE-2018-5332 bsc#1075621
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>
Acked-by: Michal Kubecek <mkubecek@suse.cz>
---
net/rds/rdma.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index 34168ee2a8df..ebabf1b81b2e 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -525,6 +525,9 @@ 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],
--
2.16.0