net/packet: fix overflow in check for tp_reserve

[ 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>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index e064e3342825..cb76ff3088e9 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3702,6 +3702,8 @@ 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;
         }