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=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 3E8A7C10F00 for ; Sat, 30 Mar 2019 09:57:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 106A5218E2 for ; Sat, 30 Mar 2019 09:57:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553939836; bh=KH93eoXpmTIyzFn4pm+LI9OvLthf6qscBa/iJ9skBT4=; h=Subject:To:Cc:From:Date:List-ID:From; b=bKdHXDxst4jKvWICiRVdCXm6YwB87jyBtHL/5MHD20dESm+G10LXCeDgWw23QdRl6 CSDU8SGlORz0q55ydR25EJcd0BRZiUIKaFP734qdDeRQHJrILWgNmhnY90H/rHw55f Pi4negI8i0PRa7rzGtJbbdH0mDhD+aBSyR8j4VRE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730632AbfC3J5O (ORCPT ); Sat, 30 Mar 2019 05:57:14 -0400 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:45155 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730644AbfC3J5M (ORCPT ); Sat, 30 Mar 2019 05:57:12 -0400 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id 9F87921E82; Sat, 30 Mar 2019 05:57:10 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Sat, 30 Mar 2019 05:57:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=EJOHKh 6f4SF2Xmv1v+hLhaHm6obUo4ixpLApegEWBDA=; b=QNWkbA/ts21ZcZ/Zcw/uuC R4E4nV+AoqtAI7J4tQKuPolLAaufn4r4Chi8KKoQerTkrAvbTQ38+H4PppTrpbKY /nKTTGpB4Sdf11Esh4EFEXJaKrWhfXahUMNYnTMzp4FiJJjOxjmOuUKXmhQ5ncpu HKYLVXljFmlRl7deenywPQI1Igiqt267HJGYRSx7Qi9BtxuYDJdaZ9cNKcXza1SA qYHCFq2pGfl9hnYFU+ZxJ5oRzWRVoS2zLYz+Z+/CjbD05rufr93WVgqRj5Gmj+Yu wmgu2HRTm3JE2vgR/J2LppOC9gQNDN+VzJi7kGKaPe53wkAdE0dOIdcfWd6bDzQQ == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedutddrkeelgddutdcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecunecujfgurhepuffvhfffkfggtgfgsehtkeertddttd flnecuhfhrohhmpeeoghhrvghgkhhhsehlihhnuhigfhhouhhnuggrthhiohhnrdhorhhg qeenucfkphepiedvrdduudelrdduieeirdelnecurfgrrhgrmhepmhgrihhlfhhrohhmpe hgrhgvgheskhhrohgrhhdrtghomhenucevlhhushhtvghrufhiiigvpedt X-ME-Proxy: Received: from localhost (unknown [62.119.166.9]) by mail.messagingengine.com (Postfix) with ESMTPA id 8DDD9E49DC; Sat, 30 Mar 2019 05:57:09 -0400 (EDT) Subject: FAILED: patch "[PATCH] binder: fix race between munmap() and direct reclaim" failed to apply to 5.0-stable tree To: tkjos@android.com, gregkh@linuxfoundation.org, joel@joelfernandes.org, stable@vger.kernel.org, tkjos@google.com Cc: From: Date: Sat, 30 Mar 2019 10:57:05 +0100 Message-ID: <155393982514974@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.0-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 5cec2d2e5839f9c0fec319c523a911e0a7fd299f Mon Sep 17 00:00:00 2001 From: Todd Kjos Date: Fri, 1 Mar 2019 15:06:06 -0800 Subject: [PATCH] binder: fix race between munmap() and direct reclaim An munmap() on a binder device causes binder_vma_close() to be called which clears the alloc->vma pointer. If direct reclaim causes binder_alloc_free_page() to be called, there is a race where alloc->vma is read into a local vma pointer and then used later after the mm->mmap_sem is acquired. This can result in calling zap_page_range() with an invalid vma which manifests as a use-after-free in zap_page_range(). The fix is to check alloc->vma after acquiring the mmap_sem (which we were acquiring anyway) and skip zap_page_range() if it has changed to NULL. Signed-off-by: Todd Kjos Reviewed-by: Joel Fernandes (Google) Cc: stable Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index 6389467670a0..195f120c4e8c 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -927,14 +927,13 @@ enum lru_status binder_alloc_free_page(struct list_head *item, 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_read_trylock(&mm->mmap_sem)) - goto err_down_write_mmap_sem_failed; - } list_lru_isolate(lru, item); spin_unlock(lock); @@ -945,10 +944,9 @@ enum lru_status binder_alloc_free_page(struct list_head *item, zap_page_range(vma, page_addr, PAGE_SIZE); trace_binder_unmap_user_end(alloc, index); - - up_read(&mm->mmap_sem); - mmput(mm); } + up_write(&mm->mmap_sem); + mmput(mm); trace_binder_unmap_kernel_start(alloc, index);