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:   Fri, 21 Aug 2020 12:15:27 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Hans Verkuil <hverkuil-cisco@...all.nl>,
        Mauro Carvalho Chehab <mchehab+huawei@...nel.org>,
        Sasha Levin <sashal@...nel.org>, linux-media@...r.kernel.org
Subject: [PATCH AUTOSEL 5.7 43/61] cec-api: prevent leaking memory through hole in structure

From: Hans Verkuil <hverkuil-cisco@...all.nl>

[ Upstream commit 6c42227c3467549ddc65efe99c869021d2f4a570 ]

Fix this smatch warning:

drivers/media/cec/core/cec-api.c:156 cec_adap_g_log_addrs() warn: check that 'log_addrs' doesn't leak information (struct has a hole after
'features')

Signed-off-by: Hans Verkuil <hverkuil-cisco@...all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/media/cec/cec-api.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/media/cec/cec-api.c b/drivers/media/cec/cec-api.c
index 17d1cb2e5f976..f922a2196b2b7 100644
--- a/drivers/media/cec/cec-api.c
+++ b/drivers/media/cec/cec-api.c
@@ -147,7 +147,13 @@ static long cec_adap_g_log_addrs(struct cec_adapter *adap,
 	struct cec_log_addrs log_addrs;
 
 	mutex_lock(&adap->lock);
-	log_addrs = adap->log_addrs;
+	/*
+	 * We use memcpy here instead of assignment since there is a
+	 * hole at the end of struct cec_log_addrs that an assignment
+	 * might ignore. So when we do copy_to_user() we could leak
+	 * one byte of memory.
+	 */
+	memcpy(&log_addrs, &adap->log_addrs, sizeof(log_addrs));
 	if (!adap->is_configured)
 		memset(log_addrs.log_addr, CEC_LOG_ADDR_INVALID,
 		       sizeof(log_addrs.log_addr));
-- 
2.25.1

Powered by blists - more mailing lists