diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index c26ee0822a05..c4ada8b6295b 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -421,6 +421,7 @@ int drm_ioctl(struct inode *inode, struct file *filp, drm_ioctl_t *func; unsigned int nr = DRM_IOCTL_NR(cmd); int retcode = -EINVAL; + char stack_kdata[128]; char *kdata = NULL; atomic_inc(&dev->ioctl_count); @@ -459,10 +460,14 @@ int drm_ioctl(struct inode *inode, struct file *filp, retcode = -EACCES; } else { if (cmd & (IOC_IN | IOC_OUT)) { - kdata = kmalloc(_IOC_SIZE(cmd), GFP_KERNEL); - if (!kdata) { - retcode = -ENOMEM; - goto err_i1; + if (_IOC_SIZE(cmd) <= sizeof(stack_kdata)) { + kdata = stack_kdata; + } else { + kdata = kmalloc(_IOC_SIZE(cmd), GFP_KERNEL); + if (!kdata) { + retcode = -ENOMEM; + goto err_i1; + } } } @@ -483,7 +488,7 @@ int drm_ioctl(struct inode *inode, struct file *filp, } err_i1: - if (kdata) + if (kdata != stack_kdata) kfree(kdata); atomic_dec(&dev->ioctl_count); if (retcode)