5.0-stable review patch. If anyone has any objections, please let me know.
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From: Eric Biggers ebiggers@google.com
commit 21d2b122732318b48c10b7262e15595ce54511d3 upstream.
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 Acked-by: Laura Abbott labbott@redhat.com Signed-off-by: Rodrigo Siqueira rodrigosiqueiramelo@gmail.com Link: https://patchwork.freedesktop.org/patch/msgid/20190226214451.195123-1-ebigge... Signed-off-by: Maxime Ripard maxime.ripard@bootlin.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/vgem/vgem_drv.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
--- 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_c 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,