lkml.org 
[lkml]   [2012]   [Mar]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/2] bluetooth: hci_ldisc: fix NULL-pointer dereference on tty_close
Hi Marcel,

On Wed, Mar 07, 2012 at 11:33:17AM -0800, Marcel Holtmann wrote:
> Hi Johan,
>
> > Do not close protocol driver until device has been unregistered.
> >
> > This fixes a race between tty_close and hci_dev_open which can result in
> > a NULL-pointer dereference.
> >
> > The line discipline closes the protocol driver while we may still have
> > hci_dev_open sleeping on the req_lock mutex resulting in a NULL-pointer
> > dereference when lock is acquired and hci_init_req called.

[...]

> what kernel version is this against? Our changes in bluetooth-next fixed
> some of the destruct handling.

This is against the latest rc as it needs to be fixed in 3.3, but I
missed a dependency to bluetooth-next as you point out below.

> Also hci_unregister_dev should be calling the destruct handler and thus
> your change is now accessing hu but it got freed already.

You're right, my patch depends on 010666a126fc ("Bluetooth: Make
hci-destruct callback optional") and 797fe796c4 ("Bluetooth: uart-ldisc:
Fix memory leak and remove destruct cb") from bluetooth-next.

But since the latter one fixes a memory leak it should have been marked
for stable as well as pushed to Linus for 3.3, right?

Thanks,
Johan


\
 
 \ /
  Last update: 2012-03-08 12:59    [W:0.086 / U:0.448 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site