Commit 8f8d28e4 authored Mar 29, 2017 by Andrey Konovalov Committed by David S. Miller Mar 30, 2017

net/packet: fix overflow in check for tp_frame_nr



When calculating rb->frames_per_block * req->tp_block_nr the result
can overflow.

Add a check that tp_block_size * tp_block_nr <= UINT_MAX.

Since frames_per_block <= tp_block_size, the expression would
never overflow.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 2b6867c2

net/packet/af_packet.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -4205,6 +4205,8 @@ 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))
		goto out;
		if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
		req->tp_frame_nr))
		goto out;

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