3.18-stable review patch. If anyone has any objections, please let me know.
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From: Kal Conley kal.conley@dectris.com
[ Upstream commit fc62814d690cf62189854464f4bd07457d5e9e50 ]
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.
Fixes: 8f8d28e4d6d8 ("net/packet: fix overflow in check for tp_frame_nr") Signed-off-by: Kal Conley kal.conley@dectris.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, 1 insertion(+), 1 deletion(-)
--- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3894,7 +3894,7 @@ static int packet_set_ring(struct sock * 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))