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  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:   Sun, 11 Dec 2022 20:24:29 +0900
From:   Vincent MAILHOL <>
To:     Johan Hovold <>
Cc:     Marc Kleine-Budde <>,,
        Oliver Neukum <>,
        Wolfgang Grandegger <>,
        "David S . Miller" <>,
        Eric Dumazet <>,
        Jakub Kicinski <>,
        Paolo Abeni <>,
        Frank Jungclaus <>,,
        Yasushi SHOJI <>,
        Stefan Mätje <>,
        Hangyu Hua <>,
        Oliver Hartkopp <>,
        Peter Fink <>,
        Jeroen Hofstee <>,
        Christoph Möhring <>,
        John Whittington <>,
        Vasanth Sadhasivan <>,
        Jimmy Assarsson <>,
        Anssi Hannula <>,
        Pavel Skripkin <>,
        Stephane Grosjean <>,
        Wolfram Sang <>,
        "Gustavo A . R . Silva" <>,
        Julia Lawall <>,
        Dongliang Mu <>,
        Sebastian Haas <>,
        Maximilian Schneider <>,
        Daniel Berglund <>,
        Olivier Sobrie <>,
        Remigiusz Kołłątaj 
        Jakob Unterwurzacher <>,
        Martin Elshuber <>,
        Bernd Krumboeck <>,,,
        Alan Stern <>,
Subject: Re: [PATCH v2 1/9] can: ems_usb: ems_usb_disconnect(): fix NULL
 pointer dereference

On Tue. 10 déc. 2022 à 20:02, Johan Hovold <> wrote:
> On Sat, Dec 10, 2022 at 06:01:49PM +0900, Vincent Mailhol wrote:
> > ems_usb sets the driver's priv data to NULL before waiting for the
> > completion of outsdanding urbs. This can results in NULL pointer
> > dereference, c.f. [1] and [2].
> Please stop making hand-wavy claims like this. There is no risk for a
> NULL-pointer deference here, and if you think otherwise you need to
> explain how that can happen in detail for each driver.


*My* mistake comes from this message from Alan [1]:

| But if a driver does make the call, it should be careful to
| ensure that the call happens _after_ the driver is finished
| using the interface-data pointer.  For example, after all
| outstanding URBs have completed, if the completion handlers
| will need to call usb_get_intfdata().

I did not pay enough attention to the "if the completion handlers will
need to call usb_get_intfdata()" part and jumped into the incorrect
conclusion that any use of usb_set_intfdata(intf, NULL) before URB
completion was erroneous.

My deep apologies for all the noise. Please forget this series and one
more time, thank you for your patience.


Powered by blists - more mailing lists