video: CVE-2018-13406

video: uvesafb: Fix integer overflow in allocation

Reference:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-4.9.y&id=7673ca3c93414faf90fa2a3c339f1f625415fecb

Change-Id: Ice9a6ab8a1e042fd32d1fe6a049855156ae4246b
Signed-off-by: Andreas Wellving <andreas.wellving@enea.com>

2 files changed, 44 insertions, 0 deletions

diff --git a/patches/cve/4.9.x.scc b/patches/cve/4.9.x.scc
index e4346d5..96a5b31 100644
--- a/patches/cve/4.9.x.scc
+++ b/patches/cve/4.9.x.scc
@@ -12,3 +12,6 @@ SRC_URI += "file://CVE-2018-9415-ARM-amba-Fix-race-condition-with-driver_overrid
 
 #CVEs fixed in 4.9.99:
 SRC_URI += "file://CVE-2017-18255-perf-core-Fix-the-perf_cpu_time_max_percent-check.patch"
+
+#CVEs fixed in 4.9.111:
+SRC_URI += "file://CVE-2018-13406-video-uvesafb-Fix-integer-overflow-in-allocation.patch"
diff --git a/patches/cve/CVE-2018-13406-video-uvesafb-Fix-integer-overflow-in-allocation.patch b/patches/cve/CVE-2018-13406-video-uvesafb-Fix-integer-overflow-in-allocation.patch
new file mode 100644
index 0000000..e0b643b
--- /dev/null
+++ b/patches/cve/CVE-2018-13406-video-uvesafb-Fix-integer-overflow-in-allocation.patch
@@ -0,0 +1,41 @@
+From 7673ca3c93414faf90fa2a3c339f1f625415fecb Mon Sep 17 00:00:00 2001
+From: Kees Cook <keescook@chromium.org>
+Date: Fri, 11 May 2018 18:24:12 +1000
+Subject: [PATCH] video: uvesafb: Fix integer overflow in allocation
+
+commit 9f645bcc566a1e9f921bdae7528a01ced5bc3713 upstream.
+
+cmap->len can get close to INT_MAX/2, allowing for an integer overflow in
+allocation. This uses kmalloc_array() instead to catch the condition.
+
+Reported-by: Dr Silvio Cesare of InfoSect <silvio.cesare@gmail.com>
+Fixes: 8bdb3a2d7df48 ("uvesafb: the driver core")
+Cc: stable@vger.kernel.org
+
+CVE: CVE-2018-13406
+Upstream-Status: Backport [https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-4.9.y&id=7673ca3c93414faf90fa2a3c339f1f625415fecb]
+
+Signed-off-by: Kees Cook <keescook@chromium.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Andreas Wellving <andreas.wellving@enea.com>
+---
+ drivers/video/fbdev/uvesafb.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/video/fbdev/uvesafb.c b/drivers/video/fbdev/uvesafb.c
+index 98af9e02959b..9fe0d0bcdf62 100644
+--- a/drivers/video/fbdev/uvesafb.c
++++ b/drivers/video/fbdev/uvesafb.c
+@@ -1059,7 +1059,8 @@ static int uvesafb_setcmap(struct fb_cmap *cmap, struct fb_info *info)
+                    info->cmap.len || cmap->start < info->cmap.start)
+                        return -EINVAL;
+ 
+-               entries = kmalloc(sizeof(*entries) * cmap->len, GFP_KERNEL);
++               entries = kmalloc_array(cmap->len, sizeof(*entries),
++                                       GFP_KERNEL);
+                if (!entries)
+                        return -ENOMEM;
+ 
+-- 
+2.19.1
+