4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kal Conley <kal.conley@xxxxxxxxxxx>
[ 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@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -4316,7 +4316,7 @@ 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))
