lkml.org 
[lkml]   [2011]   [Apr]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[34-longterm 144/209] net: packet: fix information leak to userland
    Date
    From: Vasiliy Kulikov <segooon@gmail.com>

    =====================================================================
    | This is a commit scheduled for the next v2.6.34 longterm release. |
    | If you see a problem with using this for longterm, please comment.|
    =====================================================================

    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>
    Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
    ---
    net/packet/af_packet.c | 3 ++-
    1 files changed, 2 insertions(+), 1 deletions(-)

    diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
    index 243946d..b1bc2d2 100644
    --- a/net/packet/af_packet.c
    +++ b/net/packet/af_packet.c
    @@ -1645,7 +1645,7 @@ static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
    rcu_read_lock();
    dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
    if (dev)
    - strlcpy(uaddr->sa_data, dev->name, 15);
    + strncpy(uaddr->sa_data, dev->name, 14);
    else
    memset(uaddr->sa_data, 0, 14);
    rcu_read_unlock();
    @@ -1668,6 +1668,7 @@ 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;
    rcu_read_lock();
    dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
    if (dev) {
    --
    1.7.4.4


    \
     
     \ /
      Last update: 2011-04-14 20:17    [W:0.024 / U:2.076 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site