linux-kernel - [PATCH 2/2] platform/x86/amd/pmf: Fix possible out-of-bound memory accesses

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: <20240227140500.98077-2-W_Armin@gmx.de>
Date: Tue, 27 Feb 2024 15:05:00 +0100
From: Armin Wolf <W_Armin@....de>
To: Shyam-sundar.S-k@....com
Cc: hdegoede@...hat.com,
	ilpo.jarvinen@...ux.intel.com,
	platform-driver-x86@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] platform/x86/amd/pmf: Fix possible out-of-bound memory accesses

The length of the policy buffer is not validated before accessing it,
which means that multiple out-of-bounds memory accesses can occur.

This is especially bad since userspace can load policy binaries over
debugfs.

Compile-tested only.

Signed-off-by: Armin Wolf <W_Armin@....de>
---
 drivers/platform/x86/amd/pmf/tee-if.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c
index 70d09103ab18..f2f9204b3a11 100644
--- a/drivers/platform/x86/amd/pmf/tee-if.c
+++ b/drivers/platform/x86/amd/pmf/tee-if.c
@@ -249,12 +249,18 @@ static int amd_pmf_start_policy_engine(struct amd_pmf_dev *dev)
 	u32 cookie, length;
 	int res;

+	if (dev->policy_sz < POLICY_COOKIE_LEN)
+		return -EINVAL;
+
 	cookie = dev->policy_buf[POLICY_COOKIE_OFFSET];
 	length = dev->policy_buf[POLICY_COOKIE_LEN];

 	if (cookie != POLICY_SIGN_COOKIE || !length)
 		return -EINVAL;

+	if (dev->policy_sz < length + 512)
+		return -EINVAL;
+
 	/* Update the actual length */
 	dev->policy_sz = length + 512;
 	res = amd_pmf_invoke_cmd_init(dev);
--
2.39.2