media: am437x-vpfe: exclude illegal values for enum when validing params from user...

When calling ccdc_data_size_max_bit() to validate data_sz in
vpfe_ccdc_validate_param(), it's treated as an enumeration ranging from
0 to 7 while essentially it's an 32 bit unsigned integer directly from
user space. This can make the return value of ccdc_data_size_max_bit()
underflow and bypass the following check.

To fix this, an additional check is added to the following if clause to
keep this enumaration variable in range. And if its value is not legal,
return -EINVAL properly.

Signed-off-by: Changming Liu <charley.ashbringer@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/platform/am437x/am437x-vpfe.c b/drivers/media/platform/am437x/am437x-vpfe.c
index e3f302bc2f9644140e41e4ebb18878b6a855eb66..e14a2933144bb13b38282de5ca51c3dc6edbe501 100644 (file)
--- a/drivers/media/platform/am437x/am437x-vpfe.c
+++ b/drivers/media/platform/am437x/am437x-vpfe.c
@@ -285,6 +285,7 @@ vpfe_ccdc_validate_param(struct vpfe_ccdc *ccdc,
        max_data = ccdc_data_size_max_bit(ccdcparam->data_sz);
 
        if (ccdcparam->alaw.gamma_wd > VPFE_CCDC_GAMMA_BITS_09_0 ||
+           ccdcparam->data_sz > VPFE_CCDC_DATA_8BITS ||
            max_gamma > max_data) {
                vpfe_dbg(1, vpfe, "Invalid data line select\n");
                return -EINVAL;