net-kernel: CVE-2015-8543

Fixes a NULL pointer dereference flaw in the Linux kernel's
network subsystem.
A local user could use this flaw to crash the system.

Reference:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-8543

Reference to upstream fix:
https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/patch/?id=0295617f822f630711f5af03316d3cbda6e737d4

Signen-off-by: Sona Sarmadi <sona.sarmadi@enea.com>

Signed-off-by: Martin Borg <martin.borg@enea.com>

2 files changed, 143 insertions, 0 deletions

diff --git a/recipes-kernel/linux/files/net-CVE-2015-8543.patch b/recipes-kernel/linux/files/net-CVE-2015-8543.patch
new file mode 100644
index 0000000..e9e567e
--- /dev/null
+++ b/recipes-kernel/linux/files/net-CVE-2015-8543.patch
@@ -0,0 +1,142 @@
+From 0295617f822f630711f5af03316d3cbda6e737d4 Mon Sep 17 00:00:00 2001
+From: Hannes Frederic Sowa <hannes@stressinduktion.org>
+Date: Mon, 14 Dec 2015 22:03:39 +0100
+Subject: net: add validation for the socket syscall protocol argument
+
+[ Upstream commit 79462ad02e861803b3840cc782248c7359451cd9 ]
+
+郭永刚 reported that one could simply crash the kernel as root by
+using a simple program:
+
+        int socket_fd;
+        struct sockaddr_in addr;
+        addr.sin_port = 0;
+        addr.sin_addr.s_addr = INADDR_ANY;
+        addr.sin_family = 10;
+
+        socket_fd = socket(10,3,0x40000000);
+        connect(socket_fd , &addr,16);
+
+AF_INET, AF_INET6 sockets actually only support 8-bit protocol
+identifiers. inet_sock's skc_protocol field thus is sized accordingly,
+thus larger protocol identifiers simply cut off the higher bits and
+store a zero in the protocol fields.
+
+This could lead to e.g. NULL function pointer because as a result of
+the cut off inet_num is zero and we call down to inet_autobind, which
+is NULL for raw sockets.
+
+kernel: Call Trace:
+kernel:  [<ffffffff816db90e>] ? inet_autobind+0x2e/0x70
+kernel:  [<ffffffff816db9a4>] inet_dgram_connect+0x54/0x80
+kernel:  [<ffffffff81645069>] SYSC_connect+0xd9/0x110
+kernel:  [<ffffffff810ac51b>] ? ptrace_notify+0x5b/0x80
+kernel:  [<ffffffff810236d8>] ? syscall_trace_enter_phase2+0x108/0x200
+kernel:  [<ffffffff81645e0e>] SyS_connect+0xe/0x10
+kernel:  [<ffffffff81779515>] tracesys_phase2+0x84/0x89
+
+I found no particular commit which introduced this problem.
+
+CVE: CVE-2015-8543
+Upstream-Status: Backport
+
+Cc: Cong Wang <cwang@twopensource.com>
+Reported-by: 郭永刚 <guoyonggang@360.cn>
+Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Jiri Slaby <jslaby@suse.cz>
+Signed-off-by: Sona Sarmadi <sona.sarmadi@enea.com>
+---
+ include/net/sock.h     | 1 +
+ net/ax25/af_ax25.c     | 3 +++
+ net/decnet/af_decnet.c | 3 +++
+ net/ipv4/af_inet.c     | 3 +++
+ net/ipv6/af_inet6.c    | 3 +++
+ net/irda/af_irda.c     | 3 +++
+ 6 files changed, 16 insertions(+)
+
+diff --git a/include/net/sock.h b/include/net/sock.h
+index 4d631bd..41d98f1 100644
+--- a/include/net/sock.h
++++ b/include/net/sock.h
+@@ -358,6 +358,7 @@ struct sock {
+                                sk_no_check  : 2,
+                                sk_userlocks : 4,
+                                sk_protocol  : 8,
++#define SK_PROTOCOL_MAX U8_MAX
+                                sk_type      : 16;
+        kmemcheck_bitfield_end(flags);
+        int                     sk_wmem_queued;
+diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
+index 78c474f..c4ee710 100644
+--- a/net/ax25/af_ax25.c
++++ b/net/ax25/af_ax25.c
+@@ -806,6 +806,9 @@ static int ax25_create(struct net *net, struct socket *sock, int protocol,
+        struct sock *sk;
+        ax25_cb *ax25;
+ 
++       if (protocol < 0 || protocol > SK_PROTOCOL_MAX)
++               return -EINVAL;
++
+        if (!net_eq(net, &init_net))
+                return -EAFNOSUPPORT;
+ 
+diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
+index dd4d506..c030d5c 100644
+--- a/net/decnet/af_decnet.c
++++ b/net/decnet/af_decnet.c
+@@ -677,6 +677,9 @@ static int dn_create(struct net *net, struct socket *sock, int protocol,
+ {
+        struct sock *sk;
+ 
++       if (protocol < 0 || protocol > SK_PROTOCOL_MAX)
++               return -EINVAL;
++
+        if (!net_eq(net, &init_net))
+                return -EAFNOSUPPORT;
+ 
+diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
+index cfeb85c..09f9c04 100644
+--- a/net/ipv4/af_inet.c
++++ b/net/ipv4/af_inet.c
+@@ -288,6 +288,9 @@ static int inet_create(struct net *net, struct socket *sock, int protocol,
+                if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
+                        build_ehash_secret();
+ 
++       if (protocol < 0 || protocol >= IPPROTO_MAX)
++               return -EINVAL;
++
+        sock->state = SS_UNCONNECTED;
+ 
+        /* Look for the requested type/protocol pair. */
+diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
+index 98e09df..0747e14 100644
+--- a/net/ipv6/af_inet6.c
++++ b/net/ipv6/af_inet6.c
+@@ -115,6 +115,9 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol,
+            !inet_ehash_secret)
+                build_ehash_secret();
+ 
++       if (protocol < 0 || protocol >= IPPROTO_MAX)
++               return -EINVAL;
++
+        /* Look for the requested type/protocol pair. */
+ lookup_protocol:
+        err = -ESOCKTNOSUPPORT;
+diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c
+index a5e62ef5..f8133ff 100644
+--- a/net/irda/af_irda.c
++++ b/net/irda/af_irda.c
+@@ -1105,6 +1105,9 @@ static int irda_create(struct net *net, struct socket *sock, int protocol,
+ 
+        IRDA_DEBUG(2, "%s()\n", __func__);
+ 
++       if (protocol < 0 || protocol > SK_PROTOCOL_MAX)
++               return -EINVAL;
++
+        if (net != &init_net)
+                return -EAFNOSUPPORT;
+ 
+-- 
+cgit v0.12
+
diff --git a/recipes-kernel/linux/linux-qoriq_3.12.bbappend b/recipes-kernel/linux/linux-qoriq_3.12.bbappend
index 09a3d77..cc83b93 100644
--- a/recipes-kernel/linux/linux-qoriq_3.12.bbappend
+++ b/recipes-kernel/linux/linux-qoriq_3.12.bbappend
@@ -3,5 +3,6 @@ require recipes-kernel/linux/linux-qoriq-common.inc
 FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
 
 SRC_URI += "file://ppp-CVE-2015-8569.patch \
+            file://net-CVE-2015-8543.patch \
            "