linux-kernel - Re: [PATCH v2] ppdev: fix double-free of pp->pdev->name

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20161110065712.GC29860@kroah.com>
Date:   Thu, 10 Nov 2016 07:57:12 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     Jann Horn <jann@...jh.net>
Cc:     Arnd Bergmann <arnd@...db.de>,
        Sudip Mukherjee <sudipm.mukherjee@...il.com>,
        linux-kernel@...r.kernel.org, linux-parport@...ts.infradead.org,
        Andy Lutomirski <luto@...capital.net>
Subject: Re: [PATCH v2] ppdev: fix double-free of pp->pdev->name

On Sun, Oct 30, 2016 at 11:19:24PM +0100, Jann Horn wrote:
> free_pardevice() is called by parport_unregister_device() and already frees
> pp->pdev->name, don't try to do it again.
> 
> This bug causes kernel crashes.
> 
> I found and verified this with KASAN and some added pr_emerg()s:
> 
> [   60.316568] pp_release: pp->pdev->name == ffff88039cb264c0
> [   60.316692] free_pardevice: freeing par_dev->name at ffff88039cb264c0
> [   60.316706] pp_release: kfree(ffff88039cb264c0)
> [   60.316714] ==========================================================
> [   60.316722] BUG: Double free or freeing an invalid pointer
> [   60.316731] Unexpected shadow byte: 0xFB
> [   60.316801] Object at ffff88039cb264c0, in cache kmalloc-32 size: 32
> [   60.316813] Allocated:
> [   60.316824] PID = 1695
> [   60.316869] Freed:
> [   60.316880] PID = 1695
> [   60.316935] ==========================================================
> 
> Signed-off-by: Jann Horn <jann@...jh.net>
> ---
>  drivers/char/ppdev.c | 3 ---
>  1 file changed, 3 deletions(-)

Sudip, I need an ack here before I can take this...