cec-api: prevent leaking memory through hole in structure

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@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Hans Verkuil 2020-06-26 12:44:26 +02:00 committed by Mauro Carvalho Chehab
parent 137641287e
commit 6c42227c34

View File

@ -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));