sctp: CVE-2014-7841

NULL pointer dereference in af->from_addr_param on malformed packet

Reference:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-7841

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

2 files changed, 86 insertions, 0 deletions

diff --git a/recipes-kernel/linux/files/sctp-CVE-2014-7841.patch b/recipes-kernel/linux/files/sctp-CVE-2014-7841.patch
new file mode 100644
index 0000000..0c4beb3
--- /dev/null
+++ b/recipes-kernel/linux/files/sctp-CVE-2014-7841.patch
@@ -0,0 +1,85 @@
+From 4008f1dbe6fea8114e7f79ed2d238e369dc9138f Mon Sep 17 00:00:00 2001
+From: Daniel Borkmann <dborkman@redhat.com>
+Date: Mon, 10 Nov 2014 17:54:26 +0100
+Subject: [PATCH] net: sctp: fix NULL pointer dereference in
+ af->from_addr_param on malformed packet
+
+[ Upstream commit e40607cbe270a9e8360907cb1e62ddf0736e4864 ]
+
+An SCTP server doing ASCONF will panic on malformed INIT ping-of-death
+in the form of:
+
+  ------------ INIT[PARAM: SET_PRIMARY_IP] ------------>
+
+While the INIT chunk parameter verification dissects through many things
+in order to detect malformed input, it misses to actually check parameters
+inside of parameters. E.g. RFC5061, section 4.2.4 proposes a 'set primary
+IP address' parameter in ASCONF, which has as a subparameter an address
+parameter.
+
+So an attacker may send a parameter type other than SCTP_PARAM_IPV4_ADDRESS
+or SCTP_PARAM_IPV6_ADDRESS, param_type2af() will subsequently return 0
+and thus sctp_get_af_specific() returns NULL, too, which we then happily
+dereference unconditionally through af->from_addr_param().
+
+The trace for the log:
+
+BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
+IP: [<ffffffffa01e9c62>] sctp_process_init+0x492/0x990 [sctp]
+PGD 0
+Oops: 0000 [#1] SMP
+[...]
+Pid: 0, comm: swapper Not tainted 2.6.32-504.el6.x86_64 #1 Bochs Bochs
+RIP: 0010:[<ffffffffa01e9c62>]  [<ffffffffa01e9c62>] sctp_process_init+0x492/0x990 [sctp]
+[...]
+Call Trace:
+ <IRQ>
+ [<ffffffffa01f2add>] ? sctp_bind_addr_copy+0x5d/0xe0 [sctp]
+ [<ffffffffa01e1fcb>] sctp_sf_do_5_1B_init+0x21b/0x340 [sctp]
+ [<ffffffffa01e3751>] sctp_do_sm+0x71/0x1210 [sctp]
+ [<ffffffffa01e5c09>] ? sctp_endpoint_lookup_assoc+0xc9/0xf0 [sctp]
+ [<ffffffffa01e61f6>] sctp_endpoint_bh_rcv+0x116/0x230 [sctp]
+ [<ffffffffa01ee986>] sctp_inq_push+0x56/0x80 [sctp]
+ [<ffffffffa01fcc42>] sctp_rcv+0x982/0xa10 [sctp]
+ [<ffffffffa01d5123>] ? ipt_local_in_hook+0x23/0x28 [iptable_filter]
+ [<ffffffff8148bdc9>] ? nf_iterate+0x69/0xb0
+ [<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0
+ [<ffffffff8148bf86>] ? nf_hook_slow+0x76/0x120
+ [<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0
+[...]
+
+A minimal way to address this is to check for NULL as we do on all
+other such occasions where we know sctp_get_af_specific() could
+possibly return with NULL.
+
+Fix for CVE-2014-7841
+Upstream-Status: Backport
+
+Fixes: d6de3097592b ("[SCTP]: Add the handling of "Set Primary IP Address" parameter to INIT")
+Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
+Cc: Vlad Yasevich <vyasevich@gmail.com>
+Acked-by: Neil Horman <nhorman@tuxdriver.com>
+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>
+---
+ net/sctp/sm_make_chunk.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
+index 1e06f3b..e342387 100644
+--- a/net/sctp/sm_make_chunk.c
++++ b/net/sctp/sm_make_chunk.c
+@@ -2622,6 +2622,9 @@ do_addr_param:
+                addr_param = param.v + sizeof(sctp_addip_param_t);
+ 
+                af = sctp_get_af_specific(param_type2af(param.p->type));
++               if (af == NULL)
++                       break;
++
+                af->from_addr_param(&addr, addr_param,
+                                    htons(asoc->peer.port), 0);
+ 
+-- 
+1.9.1
+
diff --git a/recipes-kernel/linux/linux-qoriq_3.12.bb b/recipes-kernel/linux/linux-qoriq_3.12.bb
index 2cd8ce9..5c67dc3 100644
--- a/recipes-kernel/linux/linux-qoriq_3.12.bb
+++ b/recipes-kernel/linux/linux-qoriq_3.12.bb
@@ -26,6 +26,7 @@ SRC_URI = "git://git.freescale.com/ppc/sdk/linux.git;nobranch=1 \
     file://0001-ALSA-CVE-2014-4652.patch \
     file://0002-ALSA-CVE-2014-4653.patch \
     file://sctp-CVE-2014-4667.patch \
+    file://sctp-CVE-2014-7841.patch \
 "
 SRCREV = "6619b8b55796cdf0cec04b66a71288edd3057229"