kernel-ipv4: CVE-2015-3636

Fixes use-after-free leading to local privilege escalation.

Reference:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-3636

Upstream fix:
https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/
patch/?id=f493b53864236c924b61ef3ccbb759ac46419a32

Signed-off-by: Sona Sarmadi <sona.sarmadi@enea.com>
Signed-off-by: Tudor Florea <tudor.florea@enea.com>

2 files changed, 39 insertions, 0 deletions

diff --git a/recipes-kernel/linux/files/ipv4-CVE-2015-3636.patch b/recipes-kernel/linux/files/ipv4-CVE-2015-3636.patch
new file mode 100644
index 0000000..ae1f4eb
--- /dev/null
+++ b/recipes-kernel/linux/files/ipv4-CVE-2015-3636.patch
@@ -0,0 +1,38 @@
+From f493b53864236c924b61ef3ccbb759ac46419a32 Mon Sep 17 00:00:00 2001
+From: "David S. Miller" <davem@davemloft.net>
+Subject: ipv4: Missing sk_nulls_node_init() in ping_unhash().
+
+[ Upstream commit a134f083e79fb4c3d0a925691e732c56911b4326 ]
+
+If we don't do that, then the poison value is left in the ->pprev
+backlink.
+
+This can cause crashes if we do a disconnect, followed by a connect().
+
+Fixes CVE-2015-3636
+Upstream-Status: Backport
+
+Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
+Reported-by: Wen Xu <hotdog3645@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Sona Sarmadi <sona.sarmadi@enea.com>
+---
+ net/ipv4/ping.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
+index b94002a..1e2e9bf 100644
+--- a/net/ipv4/ping.c
++++ b/net/ipv4/ping.c
+@@ -158,6 +158,7 @@ void ping_unhash(struct sock *sk)
+        if (sk_hashed(sk)) {
+                write_lock_bh(&ping_table.lock);
+                hlist_nulls_del(&sk->sk_nulls_node);
++               sk_nulls_node_init(&sk->sk_nulls_node);
+                sock_put(sk);
+                isk->inet_num = 0;
+                isk->inet_sport = 0;
+-- 
+cgit v0.11.2
+
diff --git a/recipes-kernel/linux/linux-yocto_3.14.bbappend b/recipes-kernel/linux/linux-yocto_3.14.bbappend
index 7037182..ebf515d 100644
--- a/recipes-kernel/linux/linux-yocto_3.14.bbappend
+++ b/recipes-kernel/linux/linux-yocto_3.14.bbappend
@@ -14,4 +14,5 @@ SRC_URI += "file://HID_CVE_patches/0005-HID-steelseries-validate-output-report-d
             file://ipv4-CVE-2015-1465.patch \
             file://net-rds-CVE-2015-2042.patch \
             file://ipv6-CVE-2015-2922.patch \
+            file://ipv4-CVE-2015-3636.patch \
            "