From mboxrd@z Thu Jan 1 00:00:00 1970 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 6275DC7EE24 for ; Mon, 5 Jun 2023 15:56:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231425AbjFEP4T (ORCPT ); Mon, 5 Jun 2023 11:56:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231281AbjFEP4S (ORCPT ); Mon, 5 Jun 2023 11:56:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BADC798; Mon, 5 Jun 2023 08:56:10 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4B630627C4; Mon, 5 Jun 2023 15:56:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B1D7C433EF; Mon, 5 Jun 2023 15:56:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685980569; bh=IpNtFuVuKEDwemMdS4OmFiuCWO+xommx26o3j8UmfWs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jSqX0XiK8oho4aB/cWScg8BnPfw3W9jVHW+yAsqniIg8EmYcq7uUYyAZZrr9v9NE/ S97rjd5OFP9KpJTapeBpC+J6IQ0l2/Cmdr9DZGCpNE/S9i/3TEpbBsHcSO+q4dnlM8 82VhuyaBYs+arx8abzKe0tssPSYVuO6pG0QeHmUxDW5rDDYANFd4i2ou3NDcUNZnq1 FVjQvir6uRbkg3H0pfRDCRkyHqm7XcdPlSv3qHZLOYPLabheChsUIqjIhsC7F5xuTT lcErf3nn/mj4diPiiJBtoE2VkHSpPXGnD6U/CVtHGv3LY2vT+DeAyD0Qu22LBgvNs9 HS9QkmjXaBWGw== Date: Mon, 5 Jun 2023 16:56:05 +0100 From: Lee Jones To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Jassi Brar , jassisinghbrar@gmail.com Subject: Re: [PATCH AUTOSEL 6.3] mailbox: mailbox-test: Fix potential double-free in mbox_test_message_write() Message-ID: <20230605155605.GA2357572@google.com> References: <20230519161348.2750641-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230519161348.2750641-1-sashal@kernel.org> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Fri, 19 May 2023, Sasha Levin wrote: > From: Lee Jones > > [ Upstream commit 2d1e952a2b8e5e92d8d55ac88a7cf7ca5ea591ad ] > > If a user can make copy_from_user() fail, there is a potential for > UAF/DF due to a lack of locking around the allocation, use and freeing > of the data buffers. > > This issue is not theoretical. I managed to author a POC for it: > > BUG: KASAN: double-free in kfree+0x5c/0xac > Free of addr ffff29280be5de00 by task poc/356 > CPU: 1 PID: 356 Comm: poc Not tainted 6.1.0-00001-g961aa6552c04-dirty #20 > Hardware name: linux,dummy-virt (DT) > Call trace: > dump_backtrace.part.0+0xe0/0xf0 > show_stack+0x18/0x40 > dump_stack_lvl+0x64/0x80 > print_report+0x188/0x48c > kasan_report_invalid_free+0xa0/0xc0 > ____kasan_slab_free+0x174/0x1b0 > __kasan_slab_free+0x18/0x24 > __kmem_cache_free+0x130/0x2e0 > kfree+0x5c/0xac > mbox_test_message_write+0x208/0x29c > full_proxy_write+0x90/0xf0 > vfs_write+0x154/0x440 > ksys_write+0xcc/0x180 > __arm64_sys_write+0x44/0x60 > invoke_syscall+0x60/0x190 > el0_svc_common.constprop.0+0x7c/0x160 > do_el0_svc+0x40/0xf0 > el0_svc+0x2c/0x6c > el0t_64_sync_handler+0xf4/0x120 > el0t_64_sync+0x18c/0x190 > > Allocated by task 356: > kasan_save_stack+0x3c/0x70 > kasan_set_track+0x2c/0x40 > kasan_save_alloc_info+0x24/0x34 > __kasan_kmalloc+0xb8/0xc0 > kmalloc_trace+0x58/0x70 > mbox_test_message_write+0x6c/0x29c > full_proxy_write+0x90/0xf0 > vfs_write+0x154/0x440 > ksys_write+0xcc/0x180 > __arm64_sys_write+0x44/0x60 > invoke_syscall+0x60/0x190 > el0_svc_common.constprop.0+0x7c/0x160 > do_el0_svc+0x40/0xf0 > el0_svc+0x2c/0x6c > el0t_64_sync_handler+0xf4/0x120 > el0t_64_sync+0x18c/0x190 > > Freed by task 357: > kasan_save_stack+0x3c/0x70 > kasan_set_track+0x2c/0x40 > kasan_save_free_info+0x38/0x5c > ____kasan_slab_free+0x13c/0x1b0 > __kasan_slab_free+0x18/0x24 > __kmem_cache_free+0x130/0x2e0 > kfree+0x5c/0xac > mbox_test_message_write+0x208/0x29c > full_proxy_write+0x90/0xf0 > vfs_write+0x154/0x440 > ksys_write+0xcc/0x180 > __arm64_sys_write+0x44/0x60 > invoke_syscall+0x60/0x190 > el0_svc_common.constprop.0+0x7c/0x160 > do_el0_svc+0x40/0xf0 > el0_svc+0x2c/0x6c > el0t_64_sync_handler+0xf4/0x120 > el0t_64_sync+0x18c/0x190 > > Signed-off-by: Lee Jones > Signed-off-by: Jassi Brar > Signed-off-by: Sasha Levin > --- > drivers/mailbox/mailbox-test.c | 7 +++++++ > 1 file changed, 7 insertions(+) Could you ensure the follow-up patch is also applied to all branches please? 8fe72b76db79d mailbox: mailbox-test: fix a locking issue in mbox_test_message_write() -- Lee Jones [李琼斯]