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From:   =?UTF-8?B?5oWV5Yas5Lqu?= <mudongliangabcd@gmail.com>
Date:   Tue, 12 Jan 2021 12:39:33 +0800
Message-ID: <CAD-N9QUap9JpVe3Fm=dAxe6EeHHh99MJctisSyE=JSNutk=xKA@mail.gmail.com>
Subject: Re: "general protection fault in sctp_ulpevent_notify_peer_addr_change"
 and "general protection fault in sctp_ulpevent_nofity_peer_addr_change"
 should share the same root cause
To:     Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc:     davem@davemloft.net, kuba@kernel.org,
        linux-kernel <linux-kernel@vger.kernel.org>,
        linux-sctp@vger.kernel.org, netdev@vger.kernel.org,
        nhorman@tuxdriver.com, vyasevich@gmail.com, rkovhaev@gmail.com,
        syzkaller-bugs <syzkaller-bugs@googlegroups.com>
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On Tue, Jan 12, 2021 at 11:27 AM Marcelo Ricardo Leitner
<marcelo.leitner@gmail.com> wrote:
>
> On Tue, Jan 12, 2021 at 10:18:00AM +0800, =E6=85=95=E5=86=AC=E4=BA=AE wro=
te:
> > Dear developers,
> >
> > I find that "general protection fault in l2cap_sock_getsockopt" and
> > "general protection fault in sco_sock_getsockopt" may be duplicated
> > bugs from the same root cause.
> >

I am sorry that the above description is for another bug group -
https://groups.google.com/g/syzkaller-bugs/c/csbAcYWGd2I. I forget to
modify this paragraph. Embarrassing :(

The correct description here should be, "I find that general
protection fault in sctp_ulpevent_notify_peer_addr_change" and
"general protection fault in sctp_ulpevent_nofity_peer_addr_change"
should share the same root cause, like the title.

> > First, by comparing the PoC similarity after own minimization, we find
> > they share the same PoC. Second, the stack traces for both bug reports
> > are the same except for the last function. And the different last
> > functions are due to a function name change (typo fix) from
> > "sctp_ulpevent_nofity_peer_addr_change" to
> > "sctp_ulpevent_notify_peer_addr_change"
>
> Not sure where you saw stack traces with this sctp function in it, but
> the syzkaller reports from 17 Feb 2020 are not related to SCTP.
>
> The one on sco_sock_getsockopt() seems to be lack of parameter
> validation: it doesn't check if optval is big enough when handling
> BT_PHY (which has the same value as SCTP_STATUS). It seems also miss a
> check on if level !=3D SOL_BLUETOOTH, but I may be wrong here.
>
> l2cap_sock_getsockopt also lacks checking optlen.
>

Please ignore my mistake, and discuss the issue of
sco/l2tp_sock_getsockopt in the thread - "general protection fault in
l2cap_sock_getsockopt" and "general protection fault in
sco_sock_getsockopt" may share the same root cause
(https://groups.google.com/g/syzkaller-bugs/c/csbAcYWGd2I)


>   Marcelo