lkml.org 
[lkml]   [2011]   [Jul]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[012/107] af_packet: prevent information leak
2.6.39-stable review patch.  If anyone has any objections, please let us know.

------------------


From: Eric Dumazet <eric.dumazet@gmail.com>

[ Upstream commit 13fcb7bd322164c67926ffe272846d4860196dc6 ]

In 2.6.27, commit 393e52e33c6c2 (packet: deliver VLAN TCI to userspace)
added a small information leak.

Add padding field and make sure its zeroed before copy to user.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
include/linux/if_packet.h | 2 ++
net/packet/af_packet.c | 2 ++
2 files changed, 4 insertions(+)

--- a/include/linux/if_packet.h
+++ b/include/linux/if_packet.h
@@ -62,6 +62,7 @@ struct tpacket_auxdata {
__u16 tp_mac;
__u16 tp_net;
__u16 tp_vlan_tci;
+ __u16 tp_padding;
};

/* Rx ring - header status */
@@ -100,6 +101,7 @@ struct tpacket2_hdr {
__u32 tp_sec;
__u32 tp_nsec;
__u16 tp_vlan_tci;
+ __u16 tp_padding;
};

#define TPACKET2_HDRLEN (TPACKET_ALIGN(sizeof(struct tpacket2_hdr)) + sizeof(struct sockaddr_ll))
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -799,6 +799,7 @@ static int tpacket_rcv(struct sk_buff *s
h.h2->tp_sec = ts.tv_sec;
h.h2->tp_nsec = ts.tv_nsec;
h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
+ h.h2->tp_padding = 0;
hdrlen = sizeof(*h.h2);
break;
default:
@@ -1727,6 +1728,7 @@ static int packet_recvmsg(struct kiocb *
aux.tp_net = skb_network_offset(skb);
aux.tp_vlan_tci = vlan_tx_tag_get(skb);

+ aux.tp_padding = 0;
put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
}




\
 
 \ /
  Last update: 2011-07-08 07:23    [W:0.930 / U:0.328 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site