media: cec: silence shift wrapping warning in __cec_s_log_addrs()

The log_addrs->log_addr_type[i] value is a u8 which is controlled by
the user and comes from the ioctl.  If it's over 31 then that results in
undefined behavior (shift wrapping) and that leads to a Smatch static
checker warning.  We already cap the value later so we can silence the
warning just by re-ordering the existing checks.

I think the UBSan checker will also catch this bug at runtime and
generate a warning.  But otherwise the bug is harmless.

Fixes: 9881fe0ca1 ("[media] cec: add HDMI CEC framework (adapter)")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Dan Carpenter 2020-05-05 10:25:56 +02:00 коммит произвёл Mauro Carvalho Chehab
Родитель 62eedb3561
Коммит 3b5af3171e
1 изменённых файлов: 4 добавлений и 4 удалений

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@ -1734,6 +1734,10 @@ int __cec_s_log_addrs(struct cec_adapter *adap,
unsigned j;
log_addrs->log_addr[i] = CEC_LOG_ADDR_INVALID;
if (log_addrs->log_addr_type[i] > CEC_LOG_ADDR_TYPE_UNREGISTERED) {
dprintk(1, "unknown logical address type\n");
return -EINVAL;
}
if (type_mask & (1 << log_addrs->log_addr_type[i])) {
dprintk(1, "duplicate logical address type\n");
return -EINVAL;
@ -1754,10 +1758,6 @@ int __cec_s_log_addrs(struct cec_adapter *adap,
dprintk(1, "invalid primary device type\n");
return -EINVAL;
}
if (log_addrs->log_addr_type[i] > CEC_LOG_ADDR_TYPE_UNREGISTERED) {
dprintk(1, "unknown logical address type\n");
return -EINVAL;
}
for (j = 0; j < feature_sz; j++) {
if ((features[j] & 0x80) == 0) {
if (op_is_dev_features)