linux-kernel - [PATCH v2 1/1] cdrom: Fix spectre-v1 gadget

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]

Message-ID: <20230612110040.849318-2-jordyzomer@google.com>
Date:   Mon, 12 Jun 2023 11:00:40 +0000
From:   Jordy Zomer <jordyzomer@...gle.com>
To:     linux-kernel@...r.kernel.org
Cc:     phil@...lpotter.co.uk, Jordy Zomer <jordyzomer@...gle.com>
Subject: [PATCH v2 1/1] cdrom: Fix spectre-v1 gadget

This patch fixes a spectre-v1 gadget in cdrom.
The gadget could be triggered by,
 speculatviely bypassing the cdi->capacity check.

Signed-off-by: Jordy Zomer <jordyzomer@...gle.com>
---
 drivers/cdrom/cdrom.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 416f723a2dbb..ecf2b458c108 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -264,6 +264,7 @@
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <linux/nospec.h>
 #include <linux/slab.h> 
 #include <linux/cdrom.h>
 #include <linux/sysctl.h>
@@ -2329,6 +2330,9 @@ static int cdrom_ioctl_media_changed(struct cdrom_device_info *cdi,
 	if (arg >= cdi->capacity)
 		return -EINVAL;
 
+	/* Prevent arg from speculatively bypassing the length check */
+	barrier_nospec();
+
 	info = kmalloc(sizeof(*info), GFP_KERNEL);
 	if (!info)
 		return -ENOMEM;
-- 
2.41.0.162.gfafddb0af9-goog