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[Yakkety,CVE-2017-100363] char: lp: fix possible integer overflow in lp_setup()

Message ID 1496812532-26491-3-git-send-email-po-hsu.lin@canonical.com
State New
Headers show

Commit Message

Po-Hsu Lin June 7, 2017, 5:15 a.m. UTC 
From: Willy Tarreau <w@1wt.eu>

CVE-2017-1000363

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)

Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
---
 drivers/char/lp.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index c4094c4..34ef474 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;
 	}