IB/rxe: check for allocation failure on elem

[ Upstream commit 4831ca9e4a8e48cb27e0a792f73250390827a228 ]

The allocation for elem may fail (especially because we're using
GFP_ATOMIC) so best to check for a null return.  This fixes a potential
null pointer dereference when assigning elem->pool.

Detected by CoverityScan CID#1357507 ("Dereference null return value")

Fixes: 8700e3e7c485 ("Soft RoCE driver")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
index c1b5f38..3b49166 100644 (file)
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c
@@ -404,6 +404,8 @@ void *rxe_alloc(struct rxe_pool *pool)
        elem = kmem_cache_zalloc(pool_cache(pool),
                                 (pool->flags & RXE_POOL_ATOMIC) ?
                                 GFP_ATOMIC : GFP_KERNEL);
+       if (!elem)
+               return NULL;
 
        elem->pool = pool;
        kref_init(&elem->ref_cnt);