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>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 2323ee3..3ac286e 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -4205,6 +4205,8 @@
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;