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 8F9AAC636D6 for ; Wed, 22 Feb 2023 12:12:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230440AbjBVMMe (ORCPT ); Wed, 22 Feb 2023 07:12:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229884AbjBVMMd (ORCPT ); Wed, 22 Feb 2023 07:12:33 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F2F1D7ABF for ; Wed, 22 Feb 2023 04:12:32 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 8312861230 for ; Wed, 22 Feb 2023 12:12:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 77DCAC433EF; Wed, 22 Feb 2023 12:12:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677067952; bh=he4m01Yz9J5kJbaOWgmc8hVDLanM8yU55P1nd85Mv5Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bSrtweo0+SQGyTqzl1e8YNrE1gVLCbgQ7qXMGWzjHKdok7fMYZmvX9AFWRY+qOT3M t63jgFTqy53pYsJ6eKDrxziKZGuMwTSCG4P1N/EcpSsurR+zasAMeJvG1jqXNY1ycv b/JuERJmrh0tAXoGcAaPGnMptM8r5K8yocorhcDfHd8UORTzx1wv3FE6rBZw7sJm2b IhuZ3ptaUwquKTAm4gVme7QLzr18u0dplrf2+Po9Z9ODDuhykympT1IR/3nfbPmnlo diDjm5pbX3YpnKGHyR//7XV2SXxCrIPT46UuxoNnaDxju73sxCTf2w3F/10C83HW2j crHUrlSoKBjUQ== From: Lee Jones To: lee@kernel.org Cc: stable@vger.kernel.org, Alessandro Astone , Todd Kjos , stable , Greg Kroah-Hartman , Carlos Llamas Subject: [PATCH v5.15.y 5/5] binder: Gracefully handle BINDER_TYPE_FDA objects with num_fds=0 Date: Wed, 22 Feb 2023 12:12:08 +0000 Message-Id: <20230222121208.898198-6-lee@kernel.org> X-Mailer: git-send-email 2.39.2.637.g21b0678d19-goog In-Reply-To: <20230222121208.898198-1-lee@kernel.org> References: <20230222121208.898198-1-lee@kernel.org> MIME-Version: 1.0 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 --- drivers/android/binder.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 730a89ebff972..c8d33c5dbe295 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2527,6 +2527,9 @@ static int binder_translate_fd_array(struct list_head *pf_head, 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", -- 2.39.2.637.g21b0678d19-goog