From: Tomas Bortoli <tomasbortoli@gmail.com>
To: vyasevich@gmail.com, nhorman@tuxdriver.com, marcelo.leitner@gmail.com
Cc: davem@davemloft.net, linux-sctp@vger.kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sctp: socket.c validate sprstat_policy
Date: Sat, 27 Oct 2018 22:43:43 +0200 [thread overview]
Message-ID: <cb41ca17-4bad-bd21-6938-aee960a8ba9b@gmail.com> (raw)
In-Reply-To: <20181027202026.32157-1-tomasbortoli@gmail.com>
On 10/27/18 10:20 PM, Tomas Bortoli wrote:
> It is possible to perform out-of-bound reads on
> sctp_getsockopt_pr_streamstatus() and on
> sctp_getsockopt_pr_assocstatus() by passing from userspace a
> sprstat_policy that overflows the abandoned_sent/abandoned_unsent
> fixed length arrays. The over-read data are directly copied/leaked
> to userspace.
>
> Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
> Reported-by: syzbot+5da0d0a72a9e7d791748@syzkaller.appspotmail.com
> ---
> v2 - added forgot ||
>
> net/sctp/socket.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index fc0386e8ff23..5290b8bd40c8 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -7083,7 +7083,8 @@ static int sctp_getsockopt_pr_assocstatus(struct sock *sk, int len,
> }
>
> policy = params.sprstat_policy;
> - if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)))
> + if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
> + __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX))
> goto out;
>
> asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
> @@ -7142,7 +7143,8 @@ static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len,
> }
>
> policy = params.sprstat_policy;
> - if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)))
> + if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
> + __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX))
> goto out;
>
> asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
>
I just realized we also have to check for less than 0 indexes..
next prev parent reply other threads:[~2018-10-27 20:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-27 20:20 [PATCH] sctp: socket.c validate sprstat_policy Tomas Bortoli
2018-10-27 20:43 ` Tomas Bortoli [this message]
2018-10-28 0:03 ` David Miller
-- strict thread matches above, loose matches on Subject: below --
2018-10-27 19:58 Tomas Bortoli
2018-10-27 20:50 ` kbuild test robot
2018-10-27 20:53 ` kbuild test robot
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