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    Subject[64/74] net: packet: fix information leak to userland
    2.6.32-longterm review patch.  If anyone has any objections, please let us know.

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

    From: Vasiliy Kulikov <segooon@gmail.com>

    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 <segooon@gmail.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Cc: Moritz Muehlenhoff <jmm@debian.org>
    [jmm: Backported to 2.6.32]
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    net/packet/af_packet.c | 3 ++-
    1 file changed, 2 insertions(+), 1 deletion(-)

    --- a/net/packet/af_packet.c
    +++ b/net/packet/af_packet.c
    @@ -1526,7 +1526,7 @@ static int packet_getname_spkt(struct so
    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);
    @@ -1549,6 +1549,7 @@ static int packet_getname(struct socket
    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;



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