Commit a963c97c authored Mar 29, 2017 by Andrey Konovalov Committed by Dennis Cagle Jul 20, 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.

Change-Id: I86aefedcb56839c85928151915358edabdc0f51c
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>

parent a18622c3

net/packet/af_packet.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -3819,6 +3819,8 @@ 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;