4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mohamed Ghannam <simo.ghannam@xxxxxxxxx> [ 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@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/rds/rdma.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/rds/rdma.c +++ b/net/rds/rdma.c @@ -525,6 +525,9 @@ int rds_rdma_extra_size(struct rds_rdma_ 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],