From 198bf1b046e370a7d3987b195cff5f1efebec3ac Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@plumgrid.com>
Date: Wed, 10 Dec 2014 20:14:55 -0800
Subject: 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: 89aa075832b0 ("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>
---
net/core/filter.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/core/filter.c b/net/core/filter.c
index 8cc3c03078b3..ec9baea10c16 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -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 */
--
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