linux-kernel - [patch -resend] spi/spidev: handle integer wrap in spidev

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 27 Jun 2012 12:02:15 +0300
From:	Dan Carpenter <dan.carpenter@...cle.com>
To:	Grant Likely <grant.likely@...retlab.ca>
Cc:	spi-devel-general@...ts.sourceforge.net,
	linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org
Subject: [patch -resend] spi/spidev: handle integer wrap in spidev_message()

"k_tmp->len" and "total" are unsigned integers.  The first message
could be close to "bufsiz" (4096) and then the next message could be
4GB which would cause an integer overflow.

Signed-off-by: Dan Carpenter <dan.carpenter@...cle.com>
---
I don't have a way to test this.  I originally sent this message on Tue,
18 Oct 2011.  I'm not totally sure what the implications are but it
seemed like there might be security implications.  I honestly don't
know.  I never received any feedback on the patch.

diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 830adbe..aab05e1 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -241,7 +241,7 @@ static int spidev_message(struct spidev_data *spidev,
 		k_tmp->len = u_tmp->len;
 
 		total += k_tmp->len;
-		if (total > bufsiz) {
+		if (total > bufsiz || total < k_tmp->len) {
 			status = -EMSGSIZE;
 			goto done;
 		}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/