From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 25 Aug 2017 23:27:14 +0300
Subject: bpf: fix oops on allocation failure
Patch-mainline: v4.14-rc1
Git-commit: f740c34ee5cf62e1fff5ebec6d0e63efcc3cdfe9
References: bsc#1109837

"err" is set to zero if bpf_map_area_alloc() fails so it means we return
ERR_PTR(0) which is NULL.  The caller, find_and_alloc_map(), is not
expecting NULL returns and will oops.

Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 kernel/bpf/sockmap.c |    1 +
 1 file changed, 1 insertion(+)

--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -523,6 +523,7 @@ static struct bpf_map *sock_map_alloc(un
 	if (err)
 		goto free_stab;
 
+	err = -ENOMEM;
 	stab->sock_map = bpf_map_area_alloc(stab->map.max_entries *
 					    sizeof(struct sock *),
 					    stab->map.numa_node);