Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9F33C6FD1A for ; Tue, 7 Mar 2023 15:37:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231473AbjCGPhr (ORCPT ); Tue, 7 Mar 2023 10:37:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231467AbjCGPh3 (ORCPT ); Tue, 7 Mar 2023 10:37:29 -0500 Received: from m12.mail.163.com (m12.mail.163.com [220.181.12.216]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 43EC78093C; Tue, 7 Mar 2023 07:36:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=iL0BA 0gE4EmKLeYtSSOEBUD0N390Hz2s7HW1XrquUFw=; b=BoNuXBr1Y5eer5pvkhVcA LBwFwIfMzogGFEbGCTI3atjdmrC+c8i6c9Tg3NtyRAn03LR/7oYbEcqQmu9OTR1a y/gwPpVN+o065CVRdYkm63SH66BpRDmFFzYAbKIY5oFKM036X4cZ8apvSf5rG2KP G5xpPkfbuL5wCD1RUNi/t0= Received: from leanderwang-LC2.localdomain (unknown [111.206.145.21]) by zwqz-smtp-mta-g2-2 (Coremail) with SMTP id _____wD3LifPWQdkZzrLCQ--.14702S2; Tue, 07 Mar 2023 23:35:43 +0800 (CST) From: Zheng Wang To: ezequiel@vanguardiasur.com.ar Cc: p.zabel@pengutronix.de, mchehab@kernel.org, linux-media@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, hackerzheng666@gmail.com, 1395428693sheep@gmail.com, alex000young@gmail.com, Zheng Wang Subject: [PATCH] media: hantro: fix use after free bug in hantro_release due to race condition Date: Tue, 7 Mar 2023 23:35:42 +0800 Message-Id: <20230307153542.1178065-1-zyytlz.wz@163.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: _____wD3LifPWQdkZzrLCQ--.14702S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7Wry3Xw4kJw47Jr4rWr4kZwb_yoW8GF13pF W7GrW7CrWjqF42gFnrJw409ayrCa4YgFW3Wrsru343AF9xtrnrGrW0y3W8AF9rtrZ3ZF45 XF48KrWrX39FvFJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0zi-eOJUUUUU= X-Originating-IP: [111.206.145.21] X-CM-SenderInfo: h2113zf2oz6qqrwthudrp/1tbiXBErU1Xl52W07wAAsc Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In hantro_probe, vpu->watchdog_work is bound with hantro_watchdog. Then hantro_end_prepare_run may be called to start the work. If we close the file or remove the module which will call hantro_release and hantro_remove to make cleanup, there may be a unfinished work. The possible sequence is as follows, which will cause a typical UAF bug. The same thing will happen in hantro_release, and use ctx after freeing it. Fix it by canceling the work before cleanup in hantro_release. CPU0 CPU1 |hantro_watchdog hantro_remove | v4l2_m2m_release | kfree(m2m_dev); | | | v4l2_m2m_get_curr_priv | m2m_dev->curr_ctx //use Signed-off-by: Zheng Wang --- drivers/media/platform/verisilicon/hantro_drv.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/media/platform/verisilicon/hantro_drv.c b/drivers/media/platform/verisilicon/hantro_drv.c index b0aeedae7b65..cf00ccaa7829 100644 --- a/drivers/media/platform/verisilicon/hantro_drv.c +++ b/drivers/media/platform/verisilicon/hantro_drv.c @@ -601,6 +601,7 @@ static int hantro_release(struct file *filp) * No need for extra locking because this was the last reference * to this file. */ + cancel_delayed_work(&vpu->watchdog_work); v4l2_m2m_ctx_release(ctx->fh.m2m_ctx); v4l2_fh_del(&ctx->fh); v4l2_fh_exit(&ctx->fh); -- 2.25.1