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* [PATCH] net/packet: fix 4gb buffer limit due to overflow check
@ 2019-02-09 20:37 Kal Conley
  2019-02-10  3:01 ` David Miller
  0 siblings, 1 reply; 4+ messages in thread
From: Kal Conley @ 2019-02-09 20:37 UTC (permalink / raw)
  To: davem
  Cc: kal.conley, Willem de Bruijn, Eric Dumazet, Greg Kroah-Hartman,
	Jeff Kirsher, Alexander Duyck, Kirill Tkhai, Vincent Whitchurch,
	Li RongQing, Magnus Karlsson, open list:NETWORKING [GENERAL],
	open list

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

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index d0945253f43b..d603a430378e 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -4291,7 +4291,7 @@ 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))
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2019-02-12 18:38 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-02-09 20:37 [PATCH] net/packet: fix 4gb buffer limit due to overflow check Kal Conley
2019-02-10  3:01 ` David Miller
2019-02-10  8:57   ` [PATCH v2] " Kal Conley
2019-02-12 18:38     ` David Miller

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