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

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[ Upstream commit 3b5af3171e2d5a73ae6f04965ed653d039904eb6 ]

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: 9881fe0ca187 ("[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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Dan Carpenter 2020-05-05 10:25:56 +02:00 committed by Greg Kroah-Hartman
parent 4f6762503f
commit 8ca0e780b4
1 changed files with 4 additions and 4 deletions
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8
drivers/media/cec/cec-adap.c
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@ -1732,6 +1732,10 @@ 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;
@ -1752,10 +1756,6 @@ 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)