Re: [PATCH] net/sctp: Prevent autoclose integer overflow in sctp_association_init()

[Xin Long]

On Thu, Dec 19, 2024 at 11:21 AM Nikolay Kuratov <kniv@xxxxxxxxxxxxxx> wrote:
>
> While by default max_autoclose equals to INT_MAX / HZ, one may set
> net.sctp.max_autoclose to UINT_MAX. There is code in
> sctp_association_init() that can consequently trigger overflow.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 9f70f46bd4c7 ("sctp: properly latch and use autoclose value from sock to association")
> Signed-off-by: Nikolay Kuratov <kniv@xxxxxxxxxxxxxx>
> ---
>  net/sctp/associola.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/sctp/associola.c b/net/sctp/associola.c
> index c45c192b7878..0b0794f164cf 100644
> --- a/net/sctp/associola.c
> +++ b/net/sctp/associola.c
> @@ -137,7 +137,8 @@ static struct sctp_association *sctp_association_init(
>                 = 5 * asoc->rto_max;
>
>         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
> -       asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ;
> +       asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
> +               (unsigned long)sp->autoclose * HZ;
>
>         /* Initializes the timers */
>         for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
> --
> 2.34.1
>
Acked-by: Xin Long <lucien.xin@xxxxxxxxx>