Messages in this thread Patch in this message | | | From | Vasiliy Kulikov <> | Subject | [PATCH 2/3] net: packet: fix information leak to userland | Date | Sun, 31 Oct 2010 20:10:28 +0300 |
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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> --- 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 3616f27..0856a13 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1719,7 +1719,7 @@ 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(); @@ -1742,6 +1742,7 @@ 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) { -- 1.7.0.4
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