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From: Kal Conley <kal.conley@dectris.com>
To: davem@davemloft.net
Cc: kal.conley@dectris.com, Willem de Bruijn <willemb@google.com>,
	Eric Dumazet <edumazet@google.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jeff Kirsher <jeffrey.t.kirsher@intel.com>,
	Alexander Duyck <alexander.h.duyck@intel.com>,
	Kirill Tkhai <ktkhai@virtuozzo.com>,
	Vincent Whitchurch <vincent.whitchurch@axis.com>,
	Li RongQing <lirongqing@baidu.com>,
	Magnus Karlsson <magnus.karlsson@intel.com>,
	netdev@vger.kernel.org (open list:NETWORKING [GENERAL]),
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] net/packet: fix 4gb buffer limit due to overflow check
Date: Sat,  9 Feb 2019 21:37:00 +0100	[thread overview]
Message-ID: <20190209203701.27252-1-kal.conley@dectris.com> (raw)

When calculating rb->frames_per_block * req->tp_block_nr the result
can overflow. Check it for overflow without limiting the total buffer
size to UINT_MAX.

This change fixes support for packet ring buffers >= UINT_MAX.
---
 net/packet/af_packet.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index d0945253f43b..d603a430378e 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -4291,7 +4291,7 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
 		rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
 		if (unlikely(rb->frames_per_block == 0))
 			goto out;
-		if (unlikely(req->tp_block_size > UINT_MAX / req->tp_block_nr))
+		if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr))
 			goto out;
 		if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
 					req->tp_frame_nr))
-- 
2.20.1


             reply	other threads:[~2019-02-09 20:38 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-09 20:37 Kal Conley [this message]
2019-02-10  3:01 ` [PATCH] net/packet: fix 4gb buffer limit due to overflow check David Miller
2019-02-10  8:57   ` [PATCH v2] " Kal Conley
2019-02-12 18:38     ` David Miller

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