diff options
| author | Eric Biggers <ebiggers@google.com> | 2019-02-26 14:08:58 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-03 06:26:26 +0200 |
| commit | 75f9e994b9fda979f542e8987bb9db9e2db82862 (patch) | |
| tree | f91a612fec2fb7f2d51ba4737c7f9934340181f6 /drivers/gpu | |
| parent | eb1e552524b40df2534f4046161658fd5c73cc63 (diff) | |
drm/vkms: fix use-after-free when drm_gem_handle_create() fails
commit 36b6c9ed45afe89045973e8dee1b004dd5372d40 upstream.
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>
Reviewed-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190226220858.214438-1-ebiggers@kernel.org
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/vkms/vkms_gem.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/drivers/gpu/drm/vkms/vkms_gem.c b/drivers/gpu/drm/vkms/vkms_gem.c index ca4a74e04977..ce394009a36c 100644 --- a/drivers/gpu/drm/vkms/vkms_gem.c +++ b/drivers/gpu/drm/vkms/vkms_gem.c @@ -110,11 +110,8 @@ 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; } |