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 AE2EFECAAD5 for ; Mon, 29 Aug 2022 11:20:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231635AbiH2LUY (ORCPT ); Mon, 29 Aug 2022 07:20:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230132AbiH2LTc (ORCPT ); Mon, 29 Aug 2022 07:19:32 -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 07B1275CC9; Mon, 29 Aug 2022 04:13:32 -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 AA6CD61242; Mon, 29 Aug 2022 11:13:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84A57C433D6; Mon, 29 Aug 2022 11:13:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661771611; bh=lbbo5zIz7LBHyIKQSGFYcidE8T1e9xUIFuGqFczWtjQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kcO+/oBeAG4cL3PJdGf1mxz/gfYZ88oHIIMLBBmdAmQ4NpA0j/7gv8aVNDwQSTYZM QiekmG9ohj/3YEnYdqE73BLcTT2hGqx1siG8hfi8+0oJwdRdSKYMl9MzG3pntmj7XW Xqw1jBQcSOeCBI3Y6bFuhPRw8I4EYwTXxgICSMTI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Liam R. Howlett" , Ondrej Mosnacek , syzbot+a7b60a176ec13cafb793@syzkaller.appspotmail.com, Carlos Llamas , Minchan Kim , "Christian Brauner (Microsoft)" , Hridya Valsaraju , Joel Fernandes , Martijn Coenen , Suren Baghdasaryan , Todd Kjos , "Matthew Wilcox (Oracle)" , =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= , Andrew Morton Subject: [PATCH 5.15 126/136] binder_alloc: add missing mmap_lock calls when using the VMA Date: Mon, 29 Aug 2022 12:59:53 +0200 Message-Id: <20220829105809.855177179@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220829105804.609007228@linuxfoundation.org> References: <20220829105804.609007228@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: Liam Howlett commit 44e602b4e52f70f04620bbbf4fe46ecb40170bde upstream. Take the mmap_read_lock() when using the VMA in binder_alloc_print_pages() and when checking for a VMA in binder_alloc_new_buf_locked(). It is worth noting binder_alloc_new_buf_locked() drops the VMA read lock after it verifies a VMA exists, but may be taken again deeper in the call stack, if necessary. Link: https://lkml.kernel.org/r/20220810160209.1630707-1-Liam.Howlett@oracle.com Fixes: a43cfc87caaf (android: binder: stop saving a pointer to the VMA) Signed-off-by: Liam R. Howlett Reported-by: Ondrej Mosnacek Reported-by: Acked-by: Carlos Llamas Tested-by: Ondrej Mosnacek Cc: Minchan Kim Cc: Christian Brauner (Microsoft) Cc: Greg Kroah-Hartman Cc: Hridya Valsaraju Cc: Joel Fernandes Cc: Martijn Coenen Cc: Suren Baghdasaryan Cc: Todd Kjos Cc: Matthew Wilcox (Oracle) Cc: "Arve Hjønnevåg" Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder_alloc.c | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-) --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -395,12 +395,15 @@ static struct binder_buffer *binder_allo size_t size, data_offsets_size; int ret; + mmap_read_lock(alloc->vma_vm_mm); if (!binder_alloc_get_vma(alloc)) { + mmap_read_unlock(alloc->vma_vm_mm); binder_alloc_debug(BINDER_DEBUG_USER_ERROR, "%d: binder_alloc_buf, no vma\n", alloc->pid); return ERR_PTR(-ESRCH); } + mmap_read_unlock(alloc->vma_vm_mm); data_offsets_size = ALIGN(data_size, sizeof(void *)) + ALIGN(offsets_size, sizeof(void *)); @@ -922,17 +925,25 @@ void binder_alloc_print_pages(struct seq * Make sure the binder_alloc is fully initialized, otherwise we might * read inconsistent state. */ - if (binder_alloc_get_vma(alloc) != NULL) { - for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) { - page = &alloc->pages[i]; - if (!page->page_ptr) - free++; - else if (list_empty(&page->lru)) - active++; - else - lru++; - } + + mmap_read_lock(alloc->vma_vm_mm); + if (binder_alloc_get_vma(alloc) == NULL) { + mmap_read_unlock(alloc->vma_vm_mm); + goto uninitialized; + } + + mmap_read_unlock(alloc->vma_vm_mm); + for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) { + page = &alloc->pages[i]; + if (!page->page_ptr) + free++; + else if (list_empty(&page->lru)) + active++; + else + lru++; } + +uninitialized: mutex_unlock(&alloc->mutex); seq_printf(m, " pages: %d:%d:%d\n", active, lru, free); seq_printf(m, " pages high watermark: %zu\n", alloc->pages_high);