From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Jann Horn <jann@thejh.net>
Cc: Arnd Bergmann <arnd@arndb.de>,
Sudip Mukherjee <sudipm.mukherjee@gmail.com>,
linux-kernel@vger.kernel.org, linux-parport@lists.infradead.org,
Andy Lutomirski <luto@amacapital.net>
Subject: Re: [PATCH v2] ppdev: fix double-free of pp->pdev->name
Date: Thu, 10 Nov 2016 07:57:12 +0100 [thread overview]
Message-ID: <20161110065712.GC29860@kroah.com> (raw)
In-Reply-To: <1477865964-4497-1-git-send-email-jann@thejh.net>
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@thejh.net>
> ---
> drivers/char/ppdev.c | 3 ---
> 1 file changed, 3 deletions(-)
Sudip, I need an ack here before I can take this...
next prev parent reply other threads:[~2016-11-10 11:33 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-30 22:19 [PATCH v2] ppdev: fix double-free of pp->pdev->name Jann Horn
2016-11-10 6:57 ` Greg Kroah-Hartman [this message]
2016-11-10 12:40 ` Sudip Mukherjee
2016-11-10 13:18 ` Arnd Bergmann
2016-11-10 13:50 ` Sudip Mukherjee
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