From: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
To: Eric Biggers <ebiggers@kernel.org>
Cc: dri-devel@lists.freedesktop.org,
Daniel Vetter <daniel.vetter@ffwll.ch>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
syzbot+e73f2fb5ed5a5df36d33@syzkaller.appspotmail.com
Subject: Re: [PATCH v2] drm/vgem: fix use-after-free when drm_gem_handle_create() fails
Date: Mon, 4 Mar 2019 20:24:40 -0300 [thread overview]
Message-ID: <20190304232440.epotc72sa5svclc2@smtp.gmail.com> (raw)
In-Reply-To: <20190226214451.195123-1-ebiggers@kernel.org>
[-- Attachment #1: Type: text/plain, Size: 1909 bytes --]
On 02/26, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> If drm_gem_handle_create() fails in vgem_gem_create(), then the
> drm_vgem_gem_object is freed twice: once when the reference is dropped
> by drm_gem_object_put_unlocked(), and again by __vgem_gem_destroy().
>
> This was hit by syzkaller using fault injection.
>
> Fix it by skipping the second free.
>
> Reported-by: syzbot+e73f2fb5ed5a5df36d33@syzkaller.appspotmail.com
> Fixes: af33a9190d02 ("drm/vgem: Enable dmabuf import interfaces")
> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Laura Abbott <labbott@redhat.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: stable@vger.kernel.org
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
> drivers/gpu/drm/vgem/vgem_drv.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
> index 5930facd6d2d8..11a8f99ba18c5 100644
> --- a/drivers/gpu/drm/vgem/vgem_drv.c
> +++ b/drivers/gpu/drm/vgem/vgem_drv.c
> @@ -191,13 +191,9 @@ static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
> ret = drm_gem_handle_create(file, &obj->base, handle);
> drm_gem_object_put_unlocked(&obj->base);
> if (ret)
> - goto err;
> + return ERR_PTR(ret);
>
> return &obj->base;
> -
> -err:
> - __vgem_gem_destroy(obj);
> - return ERR_PTR(ret);
> }
>
> static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
> --
> 2.21.0.rc2.261.ga7da99ff1b-goog
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Applied to drm-misc-fixes.
Thanks
--
Rodrigo Siqueira
https://siqueira.tech
Graduate Student
Department of Computer Science
University of São Paulo
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
next prev parent reply other threads:[~2019-03-04 23:24 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 [this message]
2019-02-26 22:08 ` [PATCH] drm/vkms: " Eric Biggers
2019-02-26 22:14 ` Chris Wilson
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190304232440.epotc72sa5svclc2@smtp.gmail.com \
--to=rodrigosiqueiramelo@gmail.com \
--cc=daniel.vetter@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=ebiggers@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=stable@vger.kernel.org \
--cc=syzbot+e73f2fb5ed5a5df36d33@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).