Commit 3617c60e authored by Hans Verkuil's avatar Hans Verkuil Committed by Zhao Wenhui
Browse files

cec-api: prevent leaking memory through hole in structure 

mainline inclusion
from mainline-v5.9-rc1
commit 6c42227c
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I82DIP
CVE: CVE-2020-36766

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=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: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: default avatarZhao Wenhui <zhaowenhui8@huawei.com>
parent e898cffa

drivers/media/cec/cec-api.c

+7 −1
Original line number Diff line number Diff line
@@ -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));