140 lines
4.3 KiB
Diff
140 lines
4.3 KiB
Diff
From 4da7dc22c91ad2c3144cb1d0d96e9611bc86da47 Mon Sep 17 00:00:00 2001
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From: Hannes Frederic Sowa <hannes@stressinduktion.org>
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Date: Mon, 14 Dec 2015 22:03:39 +0100
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Subject: [PATCH] net: add validation for the socket syscall protocol argument
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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郭永刚 reported that one could simply crash the kernel as root by
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using a simple program:
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int socket_fd;
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struct sockaddr_in addr;
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addr.sin_port = 0;
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addr.sin_addr.s_addr = INADDR_ANY;
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addr.sin_family = 10;
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socket_fd = socket(10,3,0x40000000);
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connect(socket_fd , &addr,16);
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AF_INET, AF_INET6 sockets actually only support 8-bit protocol
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identifiers. inet_sock's skc_protocol field thus is sized accordingly,
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thus larger protocol identifiers simply cut off the higher bits and
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store a zero in the protocol fields.
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This could lead to e.g. NULL function pointer because as a result of
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the cut off inet_num is zero and we call down to inet_autobind, which
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is NULL for raw sockets.
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kernel: Call Trace:
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kernel: [<ffffffff816db90e>] ? inet_autobind+0x2e/0x70
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kernel: [<ffffffff816db9a4>] inet_dgram_connect+0x54/0x80
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kernel: [<ffffffff81645069>] SYSC_connect+0xd9/0x110
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kernel: [<ffffffff810ac51b>] ? ptrace_notify+0x5b/0x80
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kernel: [<ffffffff810236d8>] ? syscall_trace_enter_phase2+0x108/0x200
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kernel: [<ffffffff81645e0e>] SyS_connect+0xe/0x10
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kernel: [<ffffffff81779515>] tracesys_phase2+0x84/0x89
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I found no particular commit which introduced this problem.
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CVE: CVE-2015-8543
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Cc: Cong Wang <cwang@twopensource.com>
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Reported-by: 郭永刚 <guoyonggang@360.cn>
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Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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---
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include/net/sock.h | 1 +
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net/ax25/af_ax25.c | 3 +++
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net/decnet/af_decnet.c | 3 +++
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net/ipv4/af_inet.c | 3 +++
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net/ipv6/af_inet6.c | 3 +++
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net/irda/af_irda.c | 3 +++
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6 files changed, 16 insertions(+)
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diff --git a/include/net/sock.h b/include/net/sock.h
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index 52d27ee924f4..2fa1fc00e8cb 100644
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--- a/include/net/sock.h
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+++ b/include/net/sock.h
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@@ -403,6 +403,7 @@ struct sock {
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sk_no_check_rx : 1,
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sk_userlocks : 4,
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sk_protocol : 8,
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+#define SK_PROTOCOL_MAX U8_MAX
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sk_type : 16;
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kmemcheck_bitfield_end(flags);
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int sk_wmem_queued;
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diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
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index ae3a47f9d1d5..fbd0acf80b13 100644
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--- a/net/ax25/af_ax25.c
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+++ b/net/ax25/af_ax25.c
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@@ -805,6 +805,9 @@ static int ax25_create(struct net *net, struct socket *sock, int protocol,
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struct sock *sk;
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ax25_cb *ax25;
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+ if (protocol < 0 || protocol > SK_PROTOCOL_MAX)
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+ return -EINVAL;
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+
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if (!net_eq(net, &init_net))
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return -EAFNOSUPPORT;
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diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
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index eebf5ac8ce18..13d6b1a6e0fc 100644
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--- a/net/decnet/af_decnet.c
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+++ b/net/decnet/af_decnet.c
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@@ -678,6 +678,9 @@ static int dn_create(struct net *net, struct socket *sock, int protocol,
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{
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struct sock *sk;
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+ if (protocol < 0 || protocol > SK_PROTOCOL_MAX)
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+ return -EINVAL;
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+
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if (!net_eq(net, &init_net))
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return -EAFNOSUPPORT;
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diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
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index 11c4ca13ec3b..5c5db6636704 100644
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--- a/net/ipv4/af_inet.c
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+++ b/net/ipv4/af_inet.c
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@@ -257,6 +257,9 @@ static int inet_create(struct net *net, struct socket *sock, int protocol,
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int try_loading_module = 0;
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int err;
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+ if (protocol < 0 || protocol >= IPPROTO_MAX)
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+ return -EINVAL;
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+
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sock->state = SS_UNCONNECTED;
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/* Look for the requested type/protocol pair. */
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diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
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index 8ec0df75f1c4..9f5137cd604e 100644
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--- a/net/ipv6/af_inet6.c
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+++ b/net/ipv6/af_inet6.c
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@@ -109,6 +109,9 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol,
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int try_loading_module = 0;
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int err;
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+ if (protocol < 0 || protocol >= IPPROTO_MAX)
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+ return -EINVAL;
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+
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/* Look for the requested type/protocol pair. */
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lookup_protocol:
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err = -ESOCKTNOSUPPORT;
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diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c
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index e6aa48b5395c..923abd6b3064 100644
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--- a/net/irda/af_irda.c
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+++ b/net/irda/af_irda.c
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@@ -1086,6 +1086,9 @@ static int irda_create(struct net *net, struct socket *sock, int protocol,
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struct sock *sk;
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struct irda_sock *self;
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+ if (protocol < 0 || protocol > SK_PROTOCOL_MAX)
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+ return -EINVAL;
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+
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if (net != &init_net)
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return -EAFNOSUPPORT;
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--
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2.5.0
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