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 X-Spam-Level: X-Spam-Status: No, score=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EBEEC43219 for ; Tue, 30 Apr 2019 11:45:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4FCE621744 for ; Tue, 30 Apr 2019 11:45:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556624748; bh=7uCSJO1BBT+F8A40pDYcZ/El2I5jL9KAAxdyytmTg3U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kRBd9fq4k0K75NvaQfMva0SUEsPItmA4JAGdk8LpBHW1T8m/YkgaEyXQLAyiliUS6 VhP8FLqm3d6qblTSCRp1Z9cBMpHuIROhscOJNhkoh8agrvfao90wS6nCFc4matJZoN WartyAv5MeWzegxiV13g3zShJB6WdWKFxTf+3MmY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730442AbfD3Lpr (ORCPT ); Tue, 30 Apr 2019 07:45:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:58134 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730432AbfD3Lpn (ORCPT ); Tue, 30 Apr 2019 07:45:43 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3FDB321744; Tue, 30 Apr 2019 11:45:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556624742; bh=7uCSJO1BBT+F8A40pDYcZ/El2I5jL9KAAxdyytmTg3U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d4tlkYsS8L1L/x5skiOXssmTLiwAyI7x/c2JeGBEqPWJwYFU5h4RIxRh5Hg33Mj6A xrpvJZ0Jv8gtn+am7/Kzg7cDEDgvhmA4KPZl67N+kZz1aNVIP9P0Z8uPqZf62QADG2 B0FFtDnSKhZds72evVZy4MT8geACpGdYyeRrG+8g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Todd Kjos , "Joel Fernandes (Google)" , syzbot+55de1eb4975dec156d8f@syzkaller.appspotmail.com Subject: [PATCH 4.19 056/100] binder: fix handling of misaligned binder object Date: Tue, 30 Apr 2019 13:38:25 +0200 Message-Id: <20190430113611.575125000@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190430113608.616903219@linuxfoundation.org> References: <20190430113608.616903219@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Todd Kjos commit 26528be6720bb40bc8844e97ee73a37e530e9c5e upstream. Fixes crash found by syzbot: kernel BUG at drivers/android/binder_alloc.c:LINE! (2) Reported-and-tested-by: syzbot+55de1eb4975dec156d8f@syzkaller.appspotmail.com Signed-off-by: Todd Kjos Reviewed-by: Joel Fernandes (Google) Cc: stable # 5.0, 4.19, 4.14 Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder_alloc.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -958,14 +958,13 @@ enum lru_status binder_alloc_free_page(s index = page - alloc->pages; page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE; + + mm = alloc->vma_vm_mm; + if (!mmget_not_zero(mm)) + goto err_mmget; + if (!down_write_trylock(&mm->mmap_sem)) + goto err_down_write_mmap_sem_failed; vma = binder_alloc_get_vma(alloc); - if (vma) { - if (!mmget_not_zero(alloc->vma_vm_mm)) - goto err_mmget; - mm = alloc->vma_vm_mm; - if (!down_write_trylock(&mm->mmap_sem)) - goto err_down_write_mmap_sem_failed; - } list_lru_isolate(lru, item); spin_unlock(lock); @@ -978,10 +977,9 @@ enum lru_status binder_alloc_free_page(s PAGE_SIZE); trace_binder_unmap_user_end(alloc, index); - - up_write(&mm->mmap_sem); - mmput(mm); } + up_write(&mm->mmap_sem); + mmput(mm); trace_binder_unmap_kernel_start(alloc, index);