net: sock: fix access via invalid file descriptor

0day robot reported the following crash:
[   21.233581] BUG: unable to handle kernel NULL pointer dereference at 0000000000000007
[   21.234709] IP: [<ffffffff8156ebda>] sk_attach_bpf+0x39/0xc2

It's due to bpf_prog_get() returning ERR_PTR.
Check it properly.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Fixes: 89aa075832 ("net: sock: allow eBPF programs to be attached to sockets")
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexei Starovoitov 2014-12-10 20:14:55 -08:00 committed by David S. Miller
parent f95b414edb
commit 198bf1b046

View file

@ -1103,8 +1103,8 @@ int sk_attach_bpf(u32 ufd, struct sock *sk)
return -EPERM;
prog = bpf_prog_get(ufd);
if (!prog)
return -EINVAL;
if (IS_ERR(prog))
return PTR_ERR(prog);
if (prog->aux->prog_type != BPF_PROG_TYPE_SOCKET_FILTER) {
/* valid fd, but invalid program type */