From 37c991e885cccd4c71a5545dbe9f7d0c2e1bbf62 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Wed, 29 Mar 2017 16:11:20 +0200 Subject: UPSTREAM: net/packet: fix overflow in check for priv area size Subtracting tp_sizeof_priv from tp_block_size and casting to int to check whether one is less then the other doesn't always work (both of them are unsigned ints). Compare them as is instead. Also cast tp_sizeof_priv to u64 before using BLK_PLUS_PRIV, as it can overflow inside BLK_PLUS_PRIV otherwise. Bug: 36725304 Upstream commit: 2b6867c2ce76c596676bec7d2d525af525fdc6e2 Signed-off-by: Andrey Konovalov Acked-by: Eric Dumazet Signed-off-by: David S. Miller Change-Id: I46bfbaf5f4a5d80f10ddce731a3030f191de4b28 --- net/packet/af_packet.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index a1b47b4a3..b51a2fb34 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3658,8 +3658,8 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) goto out; if (po->tp_version >= TPACKET_V3 && - (int)(req->tp_block_size - - BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0) + req->tp_block_size <= + BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv)) goto out; if (unlikely(req->tp_frame_size < po->tp_hdrlen + po->tp_reserve)) -- cgit v1.2.3