netdev - Re: [PATCH v2 net] sctp: potential read out of bounds in sctp_ulpevent_type

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Wed, 13 Sep 2017 17:00:19 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     dan.carpenter@...cle.com
Cc:     vyasevich@...il.com, nhorman@...driver.com,
        linux-sctp@...r.kernel.org, netdev@...r.kernel.org,
        kernel-janitors@...r.kernel.org
Subject: Re: [PATCH v2 net] sctp: potential read out of bounds in
 sctp_ulpevent_type_enabled()

From: Dan Carpenter <dan.carpenter@...cle.com>
Date: Thu, 14 Sep 2017 02:00:54 +0300

> This code causes a static checker warning because Smatch doesn't trust
> anything that comes from skb->data.  I've reviewed this code and I do
> think skb->data can be controlled by the user here.
> 
> The sctp_event_subscribe struct has 13 __u8 fields and we want to see
> if ours is non-zero.  sn_type can be any value in the 0-USHRT_MAX range.
> We're subtracting SCTP_SN_TYPE_BASE which is 1 << 15 so we could read
> either before the start of the struct or after the end.
> 
> This is a very old bug and it's surprising that it would go undetected
> for so long but my theory is that it just doesn't have a big impact so
> it would be hard to notice.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@...cle.com>
> ---
> v2:  Use reverse-christmas-tree local variable ordering.

Applied and queued up for -stable, thanks.