devlink: validate length of region addr/len

stable inclusion
from linux-4.19.111
commit 48aea14b8840a60662bac14f670ea4e265c546c8

--------------------------------

[ Upstream commit ff3b63b8 ]

DEVLINK_ATTR_REGION_CHUNK_ADDR and DEVLINK_ATTR_REGION_CHUNK_LEN
lack entries in the netlink policy. Corresponding nla_get_u64()s
may read beyond the end of the message.

Fixes: 4e54795a ("devlink: Add support for region snapshot read command")
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Reviewed-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NLi Aichun <liaichun@huawei.com>
Reviewed-by: Nguodeqing <geffrey.guo@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

net/core/devlink.c

@@ -3607,6 +3607,8 @@ static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
 	[DEVLINK_ATTR_PARAM_VALUE_CMODE] = { .type = NLA_U8 },
 	[DEVLINK_ATTR_REGION_NAME] = { .type = NLA_NUL_STRING },
 	[DEVLINK_ATTR_REGION_SNAPSHOT_ID] = { .type = NLA_U32 },
+	[DEVLINK_ATTR_REGION_CHUNK_ADDR] = { .type = NLA_U64 },
+	[DEVLINK_ATTR_REGION_CHUNK_LEN] = { .type = NLA_U64 },
 };
 
 static const struct genl_ops devlink_nl_ops[] = {