| From | Jiri Slaby <> | Subject | [PATCH 3.12 63/86] net/packet: fix overflow in check for tp_frame_nr | Date | Thu, 4 May 2017 11:04:28 +0200 |
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From: Andrey Konovalov <andreyknvl@google.com>
3.12-stable review patch. If anyone has any objections, please let me know.
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commit 8f8d28e4d6d815a391285e121c3a53a0b6cb9e7b upstream.
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> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- net/packet/af_packet.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index ed1fed3330af..d6087b4359cc 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3665,6 +3665,8 @@ 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; -- 2.12.2
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