Messages in this thread Patch in this message | | | Date | Fri, 08 Jul 2011 15:50:20 -0700 | From | Greg KH <> | Subject | [31/35] af_packet: prevent information leak |
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2.6.32-longterm review patch. If anyone has any objections, please let us know.
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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 @@ -63,6 +63,7 @@ struct tpacket_auxdata __u16 tp_mac; __u16 tp_net; __u16 tp_vlan_tci; + __u16 tp_padding; }; /* Rx ring - header status */ @@ -103,6 +104,7 @@ 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 @@ -767,6 +767,7 @@ 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 = skb->vlan_tci; + h.h2->tp_padding = 0; hdrlen = sizeof(*h.h2); break; default: @@ -1499,6 +1500,7 @@ static int packet_recvmsg(struct kiocb * aux.tp_net = skb_network_offset(skb); aux.tp_vlan_tci = skb->vlan_tci; + aux.tp_padding = 0; put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); }
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