[v2] net/packet: fix 4gb buffer limit due to overflow check
diff mbox series

Message ID 20190210085712.31622-1-kal.conley@dectris.com
State Accepted
Delegated to: David Miller
Headers show
Series
  • [v2] net/packet: fix 4gb buffer limit due to overflow check
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Commit Message

Kal Conley Feb. 10, 2019, 8:57 a.m. UTC
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@dectris.com>
---
Changes in v2:
- Add Signed-off-by and Fixes tag

 net/packet/af_packet.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

David Miller Feb. 12, 2019, 6:38 p.m. UTC | #1
From: Kal Conley <kal.conley@dectris.com>
Date: Sun, 10 Feb 2019 09:57:11 +0100

> 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@dectris.com>
> ---
> Changes in v2:
> - Add Signed-off-by and Fixes tag

Applied and queued up for -stable, thanks.

Patch
diff mbox series

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 3b1a78906bc0..1cd1d83a4be0 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -4292,7 +4292,7 @@  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))
+		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))