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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 63B0FC433DB for ; Sun, 24 Jan 2021 13:21:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 30058227BF for ; Sun, 24 Jan 2021 13:21:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725822AbhAXNVu (ORCPT ); Sun, 24 Jan 2021 08:21:50 -0500 Received: from wforward1-smtp.messagingengine.com ([64.147.123.30]:38151 "EHLO wforward1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725789AbhAXNVt (ORCPT ); Sun, 24 Jan 2021 08:21:49 -0500 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailforward.west.internal (Postfix) with ESMTP id C72A9EA1; Sun, 24 Jan 2021 08:20:42 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute4.internal (MEProxy); Sun, 24 Jan 2021 08:20:43 -0500 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=fm1; bh=bT/V4g Qhi8qc0HW2aKvlFqhkJeyNmvF8IHvjm7HeA20=; b=VmVz7WiSqEzfYjbqaHUH3a obexpcmrKLopA/tDDZ1Xt0Jzhbf+AlxalC0nBpTdfYx2PezxXn9Z68PGLucDbA1v CP/eQZsAK8Nk4UKPe7+bcZRafGVtnkwVaLBiaDPKnsh1eJunZYF4Oo9lwfZU6oxv j925R2fxCgxDAYmyBUGa+dA++WdAsaX21l+pkOiKE+VBU4lE56VrQn8PIBmFZrm3 WZmC7ffyjHNnoA3wx7SUZIp48EcSoAkuCUQBFk3EpX0YGraPYggzM5H9J4IlmNs1 Z+E6SOYfAreS3uGYoI+pSHStU+PsuogZv1yb6motnN4x3R65PvmcLy6aSotl/B8Q == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrvddugdehvdcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecunecujfgurhepuffvhfffkfggtgfgsehtkeertddttd flnecuhfhrohhmpeeoghhrvghgkhhhsehlihhnuhigfhhouhhnuggrthhiohhnrdhorhhg qeenucggtffrrghtthgvrhhnpeeiteevheeuvdfhtdfgvdeiieehheefleevveehjedute evueevledujeejgfetheenucfkphepkeefrdekiedrjeegrdeigeenucevlhhushhtvghr ufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehgrhgvgheskhhrohgrhhdrtg homh X-ME-Proxy: Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) by mail.messagingengine.com (Postfix) with ESMTPA id 889F624005B; Sun, 24 Jan 2021 08:20:41 -0500 (EST) Subject: FAILED: patch "[PATCH] btrfs: do not double free backref nodes on error" failed to apply to 4.4-stable tree To: josef@toxicpanda.com, dsterba@suse.com Cc: From: Date: Sun, 24 Jan 2021 14:20:40 +0100 Message-ID: <1611494440159166@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.4-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 49ecc679ab48b40ca799bf94b327d5284eac9e46 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 16 Dec 2020 11:22:11 -0500 Subject: [PATCH] btrfs: do not double free backref nodes on error Zygo reported the following KASAN splat: BUG: KASAN: use-after-free in btrfs_backref_cleanup_node+0x18a/0x420 Read of size 8 at addr ffff888112402950 by task btrfs/28836 CPU: 0 PID: 28836 Comm: btrfs Tainted: G W 5.10.0-e35f27394290-for-next+ #23 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack+0xbc/0xf9 ? btrfs_backref_cleanup_node+0x18a/0x420 print_address_description.constprop.8+0x21/0x210 ? record_print_text.cold.34+0x11/0x11 ? btrfs_backref_cleanup_node+0x18a/0x420 ? btrfs_backref_cleanup_node+0x18a/0x420 kasan_report.cold.10+0x20/0x37 ? btrfs_backref_cleanup_node+0x18a/0x420 __asan_load8+0x69/0x90 btrfs_backref_cleanup_node+0x18a/0x420 btrfs_backref_release_cache+0x83/0x1b0 relocate_block_group+0x394/0x780 ? merge_reloc_roots+0x4a0/0x4a0 btrfs_relocate_block_group+0x26e/0x4c0 btrfs_relocate_chunk+0x52/0x120 btrfs_balance+0xe2e/0x1900 ? check_flags.part.50+0x6c/0x1e0 ? btrfs_relocate_chunk+0x120/0x120 ? kmem_cache_alloc_trace+0xa06/0xcb0 ? _copy_from_user+0x83/0xc0 btrfs_ioctl_balance+0x3a7/0x460 btrfs_ioctl+0x24c8/0x4360 ? __kasan_check_read+0x11/0x20 ? check_chain_key+0x1f4/0x2f0 ? __asan_loadN+0xf/0x20 ? btrfs_ioctl_get_supported_features+0x30/0x30 ? kvm_sched_clock_read+0x18/0x30 ? check_chain_key+0x1f4/0x2f0 ? lock_downgrade+0x3f0/0x3f0 ? handle_mm_fault+0xad6/0x2150 ? do_vfs_ioctl+0xfc/0x9d0 ? ioctl_file_clone+0xe0/0xe0 ? check_flags.part.50+0x6c/0x1e0 ? check_flags.part.50+0x6c/0x1e0 ? check_flags+0x26/0x30 ? lock_is_held_type+0xc3/0xf0 ? syscall_enter_from_user_mode+0x1b/0x60 ? do_syscall_64+0x13/0x80 ? rcu_read_lock_sched_held+0xa1/0xd0 ? __kasan_check_read+0x11/0x20 ? __fget_light+0xae/0x110 __x64_sys_ioctl+0xc3/0x100 do_syscall_64+0x37/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f4c4bdfe427 Allocated by task 28836: kasan_save_stack+0x21/0x50 __kasan_kmalloc.constprop.18+0xbe/0xd0 kasan_kmalloc+0x9/0x10 kmem_cache_alloc_trace+0x410/0xcb0 btrfs_backref_alloc_node+0x46/0xf0 btrfs_backref_add_tree_node+0x60d/0x11d0 build_backref_tree+0xc5/0x700 relocate_tree_blocks+0x2be/0xb90 relocate_block_group+0x2eb/0x780 btrfs_relocate_block_group+0x26e/0x4c0 btrfs_relocate_chunk+0x52/0x120 btrfs_balance+0xe2e/0x1900 btrfs_ioctl_balance+0x3a7/0x460 btrfs_ioctl+0x24c8/0x4360 __x64_sys_ioctl+0xc3/0x100 do_syscall_64+0x37/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 28836: kasan_save_stack+0x21/0x50 kasan_set_track+0x20/0x30 kasan_set_free_info+0x1f/0x30 __kasan_slab_free+0xf3/0x140 kasan_slab_free+0xe/0x10 kfree+0xde/0x200 btrfs_backref_error_cleanup+0x452/0x530 build_backref_tree+0x1a5/0x700 relocate_tree_blocks+0x2be/0xb90 relocate_block_group+0x2eb/0x780 btrfs_relocate_block_group+0x26e/0x4c0 btrfs_relocate_chunk+0x52/0x120 btrfs_balance+0xe2e/0x1900 btrfs_ioctl_balance+0x3a7/0x460 btrfs_ioctl+0x24c8/0x4360 __x64_sys_ioctl+0xc3/0x100 do_syscall_64+0x37/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This occurred because we freed our backref node in btrfs_backref_error_cleanup(), but then tried to free it again in btrfs_backref_release_cache(). This is because btrfs_backref_release_cache() will cycle through all of the cache->leaves nodes and free them up. However btrfs_backref_error_cleanup() freed the backref node with btrfs_backref_free_node(), which simply kfree()d the backref node without unlinking it from the cache. Change this to a btrfs_backref_drop_node(), which does the appropriate cleanup and removes the node from the cache->leaves list, so when we go to free the remaining cache we don't trip over items we've already dropped. Fixes: 75bfb9aff45e ("Btrfs: cleanup error handling in build_backref_tree") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 02d7d7b2563b..9cadacf3ec27 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -3117,7 +3117,7 @@ void btrfs_backref_error_cleanup(struct btrfs_backref_cache *cache, list_del_init(&lower->list); if (lower == node) node = NULL; - btrfs_backref_free_node(cache, lower); + btrfs_backref_drop_node(cache, lower); } btrfs_backref_cleanup_node(cache, node);