On 02/28, Dmitry Vyukov wrote:
On Thu, Feb 28, 2019 at 12:12 AM Rodrigo Siqueira rodrigosiqueiramelo@gmail.com wrote:
On 02/26, Eric Biggers wrote:
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
drivers/gpu/drm/vkms/vkms_gem.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/vkms/vkms_gem.c b/drivers/gpu/drm/vkms/vkms_gem.c index 138b0bb325cf9..69048e73377dc 100644 --- a/drivers/gpu/drm/vkms/vkms_gem.c +++ b/drivers/gpu/drm/vkms/vkms_gem.c @@ -111,11 +111,8 @@ struct drm_gem_object *vkms_gem_create(struct drm_device *dev,
ret = drm_gem_handle_create(file, &obj->gem, handle); drm_gem_object_put_unlocked(&obj->gem);
if (ret) {drm_gem_object_release(&obj->gem);kfree(obj);
if (ret) return ERR_PTR(ret);
} return &obj->gem;}
2.21.0.rc2.261.ga7da99ff1b-goog
Hi,
Thanks for your patch! :)
The patch looks good for me. I also tested it under the IGT tests on my local VM and everything was fine.
Hi,
Patch applied to drm-misc-fixes.
Hi Rodrigo,
What are IGT tests? How can I run them?
Hi Dmitry,
IGT is a test suite focused on DRM drivers.
You can clone the project using the link below:
https://gitlab.freedesktop.org/drm/igt-gpu-tools.git
In the README, you will find the software dependencies. After you install all the required package, just use:
mkdir build && meson build && cd build && ninja
Finally, if you want to test VKMS, I recommend you to do it inside a VM.
Best Regards Rodrigo Siqueira
Reviewed-by: Rodrigo Siqueira rodrigosiqueiramelo@gmail.com
-- Rodrigo Siqueira https://siqueira.tech Graduate Student Department of Computer Science University of São Paulo
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