From: Vasiliy Kulikov Date: Wed, 10 Nov 2010 20:09:10 +0000 (-0800) Subject: net: packet: fix information leak to userland X-Git-Tag: v2.6.27.59~23 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=008c3e5897181fe8f64d6e00411e795a97b52709;p=thirdparty%2Fkernel%2Fstable.git net: packet: fix information leak to userland commit 67286640f638f5ad41a946b9a3dc75327950248f upstream. packet_getname_spkt() doesn't initialize all members of sa_data field of sockaddr struct if strlen(dev->name) < 13. This structure is then copied to userland. It leads to leaking of contents of kernel stack memory. We have to fully fill sa_data with strncpy() instead of strlcpy(). The same with packet_getname(): it doesn't initialize sll_pkttype field of sockaddr_ll. Set it to zero. Signed-off-by: Vasiliy Kulikov Signed-off-by: David S. Miller Cc: Moritz Muehlenhoff [jmm: Backported to 2.6.32] Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index ade1ebd153645..45dfb9476295d 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1208,7 +1208,7 @@ static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, uaddr->sa_family = AF_PACKET; dev = dev_get_by_index(sock_net(sk), pkt_sk(sk)->ifindex); if (dev) { - strlcpy(uaddr->sa_data, dev->name, 15); + strncpy(uaddr->sa_data, dev->name, 14); dev_put(dev); } else memset(uaddr->sa_data, 0, 14); @@ -1231,6 +1231,7 @@ static int packet_getname(struct socket *sock, struct sockaddr *uaddr, sll->sll_family = AF_PACKET; sll->sll_ifindex = po->ifindex; sll->sll_protocol = po->num; + sll->sll_pkttype = 0; dev = dev_get_by_index(sock_net(sk), po->ifindex); if (dev) { sll->sll_hatype = dev->type;