If the driver initialization fails, the vkms_exit() function might access an uninitialized or freed default_config pointer and it might double free it.
Fix both possible errors by initializing default_config only when the driver initialization succeeded. Reported-by: Louis Chauvet <louis.chau...@bootlin.com> Link: https://lore.kernel.org/all/Z5uDHcCmAwiTsGte@louis-chauvet-laptop/ Fixes: 2df7af93fdad ("drm/vkms: Add vkms_config type") Signed-off-by: José Expósito <jose.exposit...@gmail.com> --- drivers/gpu/drm/vkms/vkms_drv.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c index 7c142bfc3bd9..b6de91134a22 100644 --- a/drivers/gpu/drm/vkms/vkms_drv.c +++ b/drivers/gpu/drm/vkms/vkms_drv.c @@ -235,17 +235,19 @@ static int __init vkms_init(void) if (!config) return -ENOMEM; - default_config = config; - config->cursor = enable_cursor; config->writeback = enable_writeback; config->overlay = enable_overlay; ret = vkms_create(config); - if (ret) + if (ret) { kfree(config); + return ret; + } - return ret; + default_config = config; + + return 0; } static void vkms_destroy(struct vkms_config *config) @@ -269,9 +271,10 @@ static void vkms_destroy(struct vkms_config *config) static void __exit vkms_exit(void) { - if (default_config->dev) - vkms_destroy(default_config); + if (!default_config) + return; + vkms_destroy(default_config); kfree(default_config); } -- 2.48.1
