From: Chris Wilson <chris@chris-wilson.co.uk>
To: Eric Biggers <ebiggers@kernel.org>, dri-devel@lists.freedesktop.org
Cc: syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
linux-kernel@vger.kernel.org,
Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>,
Haneen Mohammed <hamohammed.sa@gmail.com>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
stable@vger.kernel.org
Subject: Re: [PATCH] drm/vkms: fix use-after-free when drm_gem_handle_create() fails
Date: Tue, 26 Feb 2019 22:14:49 +0000 [thread overview]
Message-ID: <155121928860.5956.12770996408502874761@skylake-alporthouse-com> (raw)
In-Reply-To: <20190226220858.214438-1-ebiggers@kernel.org>
Quoting Eric Biggers (2019-02-26 22:08:58)
> From: Eric Biggers <ebiggers@google.com>
>
> If drm_gem_handle_create() fails in vkms_gem_create(), then the
> vkms_gem_object is freed twice: once when the reference is dropped by
> drm_gem_object_put_unlocked(), and again by the extra calls to
> drm_gem_object_release() and kfree().
>
> Fix it by skipping the second release and free.
>
> This bug was originally found in the vgem driver by syzkaller using
> fault injection, but I noticed it's also present in the vkms driver.
>
> Fixes: 559e50fd34d1 ("drm/vkms: Add dumb operations")
> Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
> Cc: Haneen Mohammed <hamohammed.sa@gmail.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: stable@vger.kernel.org
> Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
-Chris
next prev parent reply other threads:[~2019-02-26 22:14 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <00000000000053fea105791276d8@google.com>
2018-10-29 11:51 ` KASAN: use-after-free Read in drm_gem_object_release Dmitry Vyukov
2019-02-26 20:47 ` [PATCH] drm/vgem: fix use-after-free when drm_gem_handle_create() fails Eric Biggers
2019-02-26 21:01 ` Chris Wilson
2019-02-26 21:30 ` Eric Biggers
2019-02-26 21:44 ` [PATCH v2] " Eric Biggers
2019-02-27 23:52 ` Laura Abbott
2019-03-04 23:24 ` Rodrigo Siqueira
2019-02-26 22:08 ` [PATCH] drm/vkms: " Eric Biggers
2019-02-26 22:14 ` Chris Wilson [this message]
2019-02-27 23:12 ` Rodrigo Siqueira
2019-02-28 6:41 ` Dmitry Vyukov
2019-03-04 23:23 ` Rodrigo Siqueira
2019-03-05 14:25 ` Dmitry Vyukov
2019-03-10 15:36 ` Rodrigo Siqueira
2019-02-27 13:23 ` [PATCH] drm/vgem: " Sasha Levin
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