From: Kees Cook <keescook@chromium.org>
Date: Wed, 28 Aug 2013 20:31:52 +0000 (+0200)
Subject: HID: picolcd_core: validate output report details
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0697d8057661db5032a55dd5b0d115262c883cb4;p=karo-tx-linux.git

HID: picolcd_core: validate output report details

commit 1e87a2456b0227ca4ab881e19a11bb99d164e792 upstream.

A HID device could send a malicious output report that would cause the
picolcd HID driver to trigger a NULL dereference during attr file writing.

[jkosina@suse.cz: changed

	report->maxfield < 1

to

	report->maxfield != 1

as suggested by Bruno].

CVE-2013-2899

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Bruno Prémont <bonbons@linux-vserver.org>
Acked-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/hid/hid-picolcd_core.c b/drivers/hid/hid-picolcd_core.c
index b48092d0e139..acbb021065ec 100644
--- a/drivers/hid/hid-picolcd_core.c
+++ b/drivers/hid/hid-picolcd_core.c
@@ -290,7 +290,7 @@ static ssize_t picolcd_operation_mode_store(struct device *dev,
 		buf += 10;
 		cnt -= 10;
 	}
-	if (!report)
+	if (!report || report->maxfield != 1)
 		return -EINVAL;
 
 	while (cnt > 0 && (buf[cnt-1] == '\n' || buf[cnt-1] == '\r'))