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.

Change-Id: I183d9adb8b90010f408b5e1d0785aa06814f4348
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Git-commit: 8f8d28e4d6d815a391285e121c3a53a0b6cb9e7b
Signed-off-by: Dennis Cagle <dcagle@codeaurora.org>
This commit is contained in:
Andrey Konovalov 2017-03-29 16:11:21 +02:00 committed by Dennis Cagle
parent 74efdfc1b9
commit dfb157d7a1

View file

@ -4127,6 +4127,8 @@ 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;