[PATCH 3.10 249/268] net/packet: fix overflow in check for tp_reserve

Willy Tarreau
2017-06-19T19:11:38Z

From: Andrey Konovalov <andreyknvl@google.com>

commit bcc5364bdcfe131e6379363f089e7b4108d35b70 upstream.

When calculating po->tp_hdrlen + po->tp_reserve the result can overflow.

Fix by checking that tp_reserve <= INT_MAX on assign.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
net/packet/af_packet.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index cea85d8..0bbb347 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3187,6 +3187,8 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
return -EBUSY;
if (copy_from_user(&val, optval, sizeof(val)))
return -EFAULT;
+ if (val > INT_MAX)
+ return -EINVAL;
po->tp_reserve = val;
return 0;
}
--
2.8.0.rc2.1.gbe9624a