On Wed, Jun 12, 2019 at 8:38 AM Neil Horman <nhorman@xxxxxxxxxxxxx> wrote:
>
> Based on comments from Xin, even after fixes for our recent syzbot
> report of cookie memory leaks, its possible to get a resend of an INIT
> chunk which would lead to us leaking cookie memory.
>
> To ensure that we don't leak cookie memory, free any previously
> allocated cookie first.
>
> ---
> Change notes
> v1->v2
> update subsystem tag in subject (davem)
> repeat kfree check for peer_random and peer_hmacs (xin)
>
> v2->v3
> net->sctp
> also free peer_chunks
>
> v3->v4
> fix subject tags
>
> Signed-off-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
> Reported-by: syzbot+f7e9153b037eac9b1df8@xxxxxxxxxxxxxxxxxxxxxxxxx
> CC: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
> CC: Xin Long <lucien.xin@xxxxxxxxx>
> CC: "David S. Miller" <davem@xxxxxxxxxxxxx>
> CC: netdev@xxxxxxxxxxxxxxx
> ---
> net/sctp/sm_make_chunk.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
> index f17908f5c4f3..9b0e5b0d701a 100644
> --- a/net/sctp/sm_make_chunk.c
> +++ b/net/sctp/sm_make_chunk.c
> @@ -2583,6 +2583,8 @@ static int sctp_process_param(struct sctp_association *asoc,
> case SCTP_PARAM_STATE_COOKIE:
> asoc->peer.cookie_len =
> ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
> + if (asoc->peer.cookie)
> + kfree(asoc->peer.cookie);
> asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp);
> if (!asoc->peer.cookie)
> retval = 0;
> @@ -2647,6 +2649,8 @@ static int sctp_process_param(struct sctp_association *asoc,
> goto fall_through;
>
> /* Save peer's random parameter */
> + if (asoc->peer.peer_random)
> + kfree(asoc->peer.peer_random);
> asoc->peer.peer_random = kmemdup(param.p,
> ntohs(param.p->length), gfp);
> if (!asoc->peer.peer_random) {
> @@ -2660,6 +2664,8 @@ static int sctp_process_param(struct sctp_association *asoc,
> goto fall_through;
>
> /* Save peer's HMAC list */
> + if (asoc->peer.peer_hmacs)
> + kfree(asoc->peer.peer_hmacs);
> asoc->peer.peer_hmacs = kmemdup(param.p,
> ntohs(param.p->length), gfp);
> if (!asoc->peer.peer_hmacs) {
> @@ -2675,6 +2681,8 @@ static int sctp_process_param(struct sctp_association *asoc,
> if (!ep->auth_enable)
> goto fall_through;
>
> + if (asoc->peer.peer_chunks)
> + kfree(asoc->peer.peer_chunks);
> asoc->peer.peer_chunks = kmemdup(param.p,
> ntohs(param.p->length), gfp);
> if (!asoc->peer.peer_chunks)
> --
> 2.20.1
>
Reviewed-by: Xin Long <lucien.xin@xxxxxxxxx>
