[PATCH 5.5 046/151] devlink: validate length of param values

From: Greg Kroah-Hartman
Date: Tue Mar 17 2020 - 07:09:17 EST


From: Jakub Kicinski <kuba@xxxxxxxxxx>

[ Upstream commit 8750939b6ad86abc3f53ec8a9683a1cded4a5654 ]

DEVLINK_ATTR_PARAM_VALUE_DATA may have different types
so it's not checked by the normal netlink policy. Make
sure the attribute length is what we expect.

Fixes: e3b7ca18ad7b ("devlink: Add param set command")
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/core/devlink.c | 31 +++++++++++++++++++------------
1 file changed, 19 insertions(+), 12 deletions(-)

--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -3352,34 +3352,41 @@ devlink_param_value_get_from_info(const
struct genl_info *info,
union devlink_param_value *value)
{
+ struct nlattr *param_data;
int len;

- if (param->type != DEVLINK_PARAM_TYPE_BOOL &&
- !info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA])
+ param_data = info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA];
+
+ if (param->type != DEVLINK_PARAM_TYPE_BOOL && !param_data)
return -EINVAL;

switch (param->type) {
case DEVLINK_PARAM_TYPE_U8:
- value->vu8 = nla_get_u8(info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA]);
+ if (nla_len(param_data) != sizeof(u8))
+ return -EINVAL;
+ value->vu8 = nla_get_u8(param_data);
break;
case DEVLINK_PARAM_TYPE_U16:
- value->vu16 = nla_get_u16(info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA]);
+ if (nla_len(param_data) != sizeof(u16))
+ return -EINVAL;
+ value->vu16 = nla_get_u16(param_data);
break;
case DEVLINK_PARAM_TYPE_U32:
- value->vu32 = nla_get_u32(info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA]);
+ if (nla_len(param_data) != sizeof(u32))
+ return -EINVAL;
+ value->vu32 = nla_get_u32(param_data);
break;
case DEVLINK_PARAM_TYPE_STRING:
- len = strnlen(nla_data(info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA]),
- nla_len(info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA]));
- if (len == nla_len(info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA]) ||
+ len = strnlen(nla_data(param_data), nla_len(param_data));
+ if (len == nla_len(param_data) ||
len >= __DEVLINK_PARAM_MAX_STRING_VALUE)
return -EINVAL;
- strcpy(value->vstr,
- nla_data(info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA]));
+ strcpy(value->vstr, nla_data(param_data));
break;
case DEVLINK_PARAM_TYPE_BOOL:
- value->vbool = info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA] ?
- true : false;
+ if (param_data && nla_len(param_data))
+ return -EINVAL;
+ value->vbool = nla_get_flag(param_data);
break;
}
return 0;