From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org by pdx-caf-mail.web.codeaurora.org (Dovecot) with LMTP id Onx+MlJIGVtPRwAAmS7hNA ; Thu, 07 Jun 2018 15:00:04 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 55593607E7; Thu, 7 Jun 2018 15:00:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by smtp.codeaurora.org (Postfix) with ESMTP id C4DD8601C3; Thu, 7 Jun 2018 15:00:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C4DD8601C3 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935760AbeFGPAC (ORCPT + 25 others); Thu, 7 Jun 2018 11:00:02 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41307 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935208AbeFGO76 (ORCPT ); Thu, 7 Jun 2018 10:59:58 -0400 Received: from [148.252.241.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1fQvbd-0005Zw-HC; Thu, 07 Jun 2018 15:09:37 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1fQvb8-00034L-09; Thu, 07 Jun 2018 15:09:06 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Greg Kroah-Hartman" , "Eric Biggers" , "syzbot" Date: Thu, 07 Jun 2018 15:05:21 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 246/410] binder: check for binder_thread allocation failure in binder_poll() In-Reply-To: X-SA-Exim-Connect-IP: 148.252.241.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.57-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers commit f88982679f54f75daa5b8eff3da72508f1e7422f upstream. If the kzalloc() in binder_get_thread() fails, binder_poll() dereferences the resulting NULL pointer. Fix it by returning POLLERR if the memory allocation failed. This bug was found by syzkaller using fault injection. Reported-by: syzbot Fixes: 457b9a6f09f0 ("Staging: android: add binder driver") Signed-off-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.16: - Drop the binder global lock before returning - Adjust filename] Signed-off-by: Ben Hutchings --- --- a/drivers/staging/android/binder.c +++ b/drivers/staging/android/binder.c @@ -2572,6 +2572,10 @@ static unsigned int binder_poll(struct f binder_lock(__func__); thread = binder_get_thread(proc); + if (!thread) { + binder_unlock(__func__); + return POLLERR; + } wait_for_proc_work = thread->transaction_stack == NULL && list_empty(&thread->todo) && thread->return_error == BR_OK;