On Fri, Aug 14, 2020 at 6:20 AM Alexander Potapenko <glider@xxxxxxxxxx> wrote:
>
>
>
> On Fri, Aug 14, 2020, 13:04 Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> wrote:
>>
>> From: Eric Dumazet <edumazet@xxxxxxxxxx>
>> net/can/j1939/socket.c | 5 +++++
>> 1 file changed, 5 insertions(+)
>>
>> diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
>> index 78ff9b3f1d40..b634b680177f 100644
>> --- a/net/can/j1939/socket.c
>> +++ b/net/can/j1939/socket.c
>> @@ -553,6 +553,11 @@ static int j1939_sk_connect(struct socket *sock, struct sockaddr *uaddr,
>> static void j1939_sk_sock2sockaddr_can(struct sockaddr_can *addr,
>> const struct j1939_sock *jsk, int peer)
>> {
>> + /* There are two holes (2 bytes and 3 bytes) to clear to avoid
>> + * leaking kernel information to user space.
>> + */
>
>
> Do we want to keep these "2 bytes and 3 bytes' in sync with the struct layout in the future? Maybe it's not worth it to mention the exact sizes?
struct is uapi, you will have a hard time trying to use these holes,
since old kernels were sending crap/garbage/passwords ;)
