From: Willy Tarreau <w@1wt.eu>
Date: Tue, 16 May 2017 17:18:55 +0000 (+0200)
Subject: char: lp: fix possible integer overflow in lp_setup()
X-Git-Tag: v4.1.12-106.0.20170720_1900~68
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=42bf9ea74dfa59a61c5b5b92805b4e75dd0532c4;p=users%2Fjedix%2Flinux-maple.git

char: lp: fix possible integer overflow in lp_setup()

The lp_setup() code doesn't apply any bounds checking when passing
"lp=none", and only in this case, resulting in an overflow of the
parport_nr[] array. All versions in Git history are affected.

Reported-By: Roee Hay <roee.hay@hcl.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 3e21f4af170bebf47c187c1ff8bf155583c9f3b1)

Orabug: 26174869
CVE-2017-1000363

Signed-off-by: Kirtikar Kashyap <kirtikar.kashyap@oracle.com>
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>
---

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index c4094c4e22c1..34ef474a3923 100644
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -859,7 +859,11 @@ static int __init lp_setup (char *str)
 	} else if (!strcmp(str, "auto")) {
 		parport_nr[0] = LP_PARPORT_AUTO;
 	} else if (!strcmp(str, "none")) {
-		parport_nr[parport_ptr++] = LP_PARPORT_NONE;
+		if (parport_ptr < LP_NO)
+			parport_nr[parport_ptr++] = LP_PARPORT_NONE;
+		else
+			printk(KERN_INFO "lp: too many ports, %s ignored.\n",
+			       str);
 	} else if (!strcmp(str, "reset")) {
 		reset = 1;
 	}