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 C52F7C677F1 for ; Thu, 23 Feb 2023 13:13:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234506AbjBWNNS (ORCPT ); Thu, 23 Feb 2023 08:13:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234538AbjBWNNP (ORCPT ); Thu, 23 Feb 2023 08:13:15 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6F6D570B9 for ; Thu, 23 Feb 2023 05:12:39 -0800 (PST) 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 sin.source.kernel.org (Postfix) with ESMTPS id 0DFB3CE206B for ; Thu, 23 Feb 2023 13:12:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2DE29C4339B; Thu, 23 Feb 2023 13:12:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1677157956; bh=QcCbxXXtoVbGVt6RptA+ZzTzyyKRNhQjmdnc1BIyMoY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y9npWFNZwKs6XxYiV+ALjWVTKMCCBUr1pwvbXMblQMt/f6S4FIXdiSNU+B4OZIp8z +mrf6J5CU3IEM/zXnrafFCf3IUmshyf6UzkCXbAUzCEcGmiLJkaTHHwbEsFFxnu98/ 7LvfUxd1T3B7QzdDSVbHF7dr+2tf/XmOZypB324g= From: Greg Kroah-Hartman To: stable@vger.kernel.org, lee@kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Todd Kjos , stable , Alessandro Astone , Carlos Llamas Subject: [PATCH 5.15 27/36] binder: Gracefully handle BINDER_TYPE_FDA objects with num_fds=0 Date: Thu, 23 Feb 2023 14:07:03 +0100 Message-Id: <20230223130430.322049293@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230223130429.072633724@linuxfoundation.org> References: <20230223130429.072633724@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alessandro Astone commit ef38de9217a04c9077629a24652689d8fdb4c6c6 upstream. Some android userspace is sending BINDER_TYPE_FDA objects with num_fds=0. Like the previous patch, this is reproducible when playing a video. Before commit 09184ae9b575 BINDER_TYPE_FDA objects with num_fds=0 were 'correctly handled', as in no fixup was performed. After commit 09184ae9b575 we aggregate fixup and skip regions in binder_ptr_fixup structs and distinguish between the two by using the skip_size field: if it's 0, then it's a fixup, otherwise skip. When processing BINDER_TYPE_FDA objects with num_fds=0 we add a skip region of skip_size=0, and this causes issues because now binder_do_deferred_txn_copies will think this was a fixup region. To address that, return early from binder_translate_fd_array to avoid adding an empty skip region. Fixes: 09184ae9b575 ("binder: defer copies of pre-patched txn data") Acked-by: Todd Kjos Cc: stable Signed-off-by: Alessandro Astone Link: https://lore.kernel.org/r/20220415120015.52684-1-ales.astone@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Carlos Llamas Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2527,6 +2527,9 @@ static int binder_translate_fd_array(str struct binder_proc *proc = thread->proc; int ret; + if (fda->num_fds == 0) + return 0; + fd_buf_size = sizeof(u32) * fda->num_fds; if (fda->num_fds >= SIZE_MAX / sizeof(u32)) { binder_user_error("%d:%d got transaction with invalid number of fds (%lld)\n",