From: Hans Verkuil hverkuil-cisco@xs4all.nl

mainline inclusion from mainline-v5.9-rc1 commit 6c42227c3467549ddc65efe99c869021d2f4a570 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/?i...

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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 Signed-off-by: Zhao Wenhui zhaowenhui8@huawei.com --- 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 4961573850d5..b2b3f779592f 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));