From: Dan Carpenter <dan.carpenter@oracle.com>
To: Todd Kjos <tkjos@google.com>
Cc: "Martijn Coenen" <maco@android.com>,
"open list:ANDROID DRIVERS" <devel@driverdev.osuosl.org>,
"Greg KH" <gregkh@linuxfoundation.org>,
LKML <linux-kernel@vger.kernel.org>,
stable <stable@vger.kernel.org>,
"Arve Hjønnevåg" <arve@android.com>,
"Martijn Coenen" <maco@google.com>,
"Joel Fernandes" <joel@joelfernandes.org>,
kernel-team@android.com,
"Christian Brauner" <christian@brauner.io>
Subject: Re: [PATCH] binder: make sure fd closes complete
Date: Fri, 3 Sep 2021 11:06:17 +0300 [thread overview]
Message-ID: <20210903080617.GA1957@kadam> (raw)
In-Reply-To: <CAHRSSExONtUFu0Mb8uJeVKcyDYb8=1PO7a=aQ=DUEpA5kAcTQA@mail.gmail.com>
On Thu, Sep 02, 2021 at 08:35:35AM -0700, Todd Kjos wrote:
> On Tue, Aug 31, 2021 at 12:24 AM Martijn Coenen <maco@android.com> wrote:
> >
> > On Mon, Aug 30, 2021 at 9:51 PM 'Todd Kjos' via kernel-team
> > <kernel-team@android.com> wrote:
> > >
> > > During BC_FREE_BUFFER processing, the BINDER_TYPE_FDA object
> > > cleanup may close 1 or more fds. The close operations are
> > > completed using the task work mechanism -- which means the thread
> > > needs to return to userspace or the file object may never be
> > > dereferenced -- which can lead to hung processes.
> > >
> > > Force the binder thread back to userspace if an fd is closed during
> > > BC_FREE_BUFFER handling.
> > >
> > > Signed-off-by: Todd Kjos <tkjos@google.com>
> > Reviewed-by: Martijn Coenen <maco@android.com>
>
> Please also add to stable releases 5.4 and later.
It would be better if this had a fixes tag so we knew which is the first
buggy commit.
There was a long Project Zero article about the Bad Binder exploit
because commit f5cb779ba163 ("ANDROID: binder: remove waitqueue when
thread exits.") was marked as # 4.14 but it didn't have a Fixes tag and
the actual buggy commit was in 4.9.
regards,
dan carpenter
next prev parent reply other threads:[~2021-09-03 8:06 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-30 19:51 [PATCH] binder: make sure fd closes complete Todd Kjos
2021-08-31 7:24 ` Christian Brauner
2021-08-31 7:24 ` Martijn Coenen
2021-09-02 15:35 ` Todd Kjos
2021-09-02 16:11 ` Greg KH
2021-09-03 8:06 ` Dan Carpenter [this message]
2021-09-03 19:38 ` Todd Kjos
2021-09-14 7:01 ` Greg KH
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