Commit 952fad8e authored Feb 13, 2018 by Eric Dumazet Committed by Alexei Starovoitov Feb 13, 2018

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: 1aa12bdf ("bpf: sockmap, add sock close() hook to remove socks")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

parent 9a3efb6b

kernel/bpf/sockmap.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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;

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