35 lines
1.2 KiB
Diff
35 lines
1.2 KiB
Diff
From: Andrey Konovalov <andreyknvl@google.com>
|
|
Date: Wed, 29 Mar 2017 16:11:20 +0200
|
|
Subject: net/packet: fix overflow in check for priv area size
|
|
Origin: https://patchwork.ozlabs.org/patch/744811/
|
|
Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2017-7308
|
|
|
|
Subtracting tp_sizeof_priv from tp_block_size and casting to int
|
|
to check whether one is less then the other doesn't always work
|
|
(both of them are unsigned ints).
|
|
|
|
Compare them as is instead.
|
|
|
|
Also cast tp_sizeof_priv to u64 before using BLK_PLUS_PRIV, as
|
|
it can overflow inside BLK_PLUS_PRIV otherwise.
|
|
|
|
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
|
|
Acked-by: Eric Dumazet <edumazet@google.com>
|
|
---
|
|
net/packet/af_packet.c | 4 ++--
|
|
1 file changed, 2 insertions(+), 2 deletions(-)
|
|
|
|
--- a/net/packet/af_packet.c
|
|
+++ b/net/packet/af_packet.c
|
|
@@ -4235,8 +4235,8 @@ static int packet_set_ring(struct sock *
|
|
if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
|
|
goto out;
|
|
if (po->tp_version >= TPACKET_V3 &&
|
|
- (int)(req->tp_block_size -
|
|
- BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
|
|
+ req->tp_block_size <=
|
|
+ BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv))
|
|
goto out;
|
|
if (unlikely(req->tp_frame_size < po->tp_hdrlen +
|
|
po->tp_reserve))
|