[PATCH 3.18 15/68] net/packet: fix overflow in check for tp_reserve

Greg Kroah-Hartman
2017-05-05T18:33:11Z

From: Andrey Konovalov <andreyknvl@google.com>

[ Upstream commit bcc5364bdcfe131e6379363f089e7b4108d35b70 ]

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/packet/af_packet.c | 2 ++
1 file changed, 2 insertions(+)

--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3314,6 +3314,8 @@ packet_setsockopt(struct socket *sock, i
return -EBUSY;
if (copy_from_user(&val, optval, sizeof(val)))
return -EFAULT;
+ if (val > INT_MAX)
+ return -EINVAL;
po->tp_reserve = val;
return 0;
}