From 952fad8e323975c4e826b659087d2648777594a6 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 13 Feb 2018 15:33:52 -0800 Subject: [PATCH] bpf: fix sock_map_alloc() error path In case user program provides silly parameters, we want a map_alloc() handler to return an error, not a NULL pointer, otherwise we crash later in find_and_alloc_map() Fixes: 1aa12bdf1bfb ("bpf: sockmap, add sock close() hook to remove socks") Signed-off-by: Eric Dumazet Reported-by: syzbot Acked-by: John Fastabend Signed-off-by: Alexei Starovoitov --- kernel/bpf/sockmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c index 48c33417d13c..a927e89dad6e 100644 --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -521,8 +521,8 @@ static struct smap_psock *smap_init_psock(struct sock *sock, static struct bpf_map *sock_map_alloc(union bpf_attr *attr) { struct bpf_stab *stab; - int err = -EINVAL; u64 cost; + int err; if (!capable(CAP_NET_ADMIN)) return ERR_PTR(-EPERM); @@ -547,6 +547,7 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr) /* make sure page count doesn't overflow */ cost = (u64) stab->map.max_entries * sizeof(struct sock *); + err = -EINVAL; if (cost >= U32_MAX - PAGE_SIZE) goto free_stab; -- 2.30.2