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=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 7E7B8C25AE8 for ; Mon, 26 Jul 2021 16:36:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D6306056B for ; Mon, 26 Jul 2021 16:36:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240179AbhGZPzE (ORCPT ); Mon, 26 Jul 2021 11:55:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:51470 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236333AbhGZPeS (ORCPT ); Mon, 26 Jul 2021 11:34:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id DE27860F5A; Mon, 26 Jul 2021 16:14:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627316085; bh=coqtVgG0wSPKKNK308MudOo7idkgrWjPnSCtxuFbz0I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wW5YIz2drNka3o5GyxSVJ53LO09Te7PY+FW+R3FmDo+IKvX2tZR0okDxQwIptVfeu YTAWu6TCFcj5gjPLorZxgkkqa7jboHRXZ1Dr3M4Iroy8OOvdWrLEbonh2PgHKu+Mv8 LjpK65BLm6asJSwWTswUzuO4fNy0Ial4H7A1QzuM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Filipe Manana , Anand Jain , David Sterba Subject: [PATCH 5.13 181/223] btrfs: check for missing device in btrfs_trim_fs Date: Mon, 26 Jul 2021 17:39:33 +0200 Message-Id: <20210726153852.114638618@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210726153846.245305071@linuxfoundation.org> References: <20210726153846.245305071@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Anand Jain commit 16a200f66ede3f9afa2e51d90ade017aaa18d213 upstream. A fstrim on a degraded raid1 can trigger the following null pointer dereference: BTRFS info (device loop0): allowing degraded mounts BTRFS info (device loop0): disk space caching is enabled BTRFS info (device loop0): has skinny extents BTRFS warning (device loop0): devid 2 uuid 97ac16f7-e14d-4db1-95bc-3d489b424adb is missing BTRFS warning (device loop0): devid 2 uuid 97ac16f7-e14d-4db1-95bc-3d489b424adb is missing BTRFS info (device loop0): enabling ssd optimizations BUG: kernel NULL pointer dereference, address: 0000000000000620 PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 0 PID: 4574 Comm: fstrim Not tainted 5.13.0-rc7+ #31 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:btrfs_trim_fs+0x199/0x4a0 [btrfs] RSP: 0018:ffff959541797d28 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff946f84eca508 RCX: a7a67937adff8608 RDX: ffff946e8122d000 RSI: 0000000000000000 RDI: ffffffffc02fdbf0 RBP: ffff946ea4615000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: ffff946e8122d960 R12: 0000000000000000 R13: ffff959541797db8 R14: ffff946e8122d000 R15: ffff959541797db8 FS: 00007f55917a5080(0000) GS:ffff946f9bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000620 CR3: 000000002d2c8001 CR4: 00000000000706f0 Call Trace: btrfs_ioctl_fitrim+0x167/0x260 [btrfs] btrfs_ioctl+0x1c00/0x2fe0 [btrfs] ? selinux_file_ioctl+0x140/0x240 ? syscall_trace_enter.constprop.0+0x188/0x240 ? __x64_sys_ioctl+0x83/0xb0 __x64_sys_ioctl+0x83/0xb0 Reproducer: $ mkfs.btrfs -fq -d raid1 -m raid1 /dev/loop0 /dev/loop1 $ mount /dev/loop0 /btrfs $ umount /btrfs $ btrfs dev scan --forget $ mount -o degraded /dev/loop0 /btrfs $ fstrim /btrfs The reason is we call btrfs_trim_free_extents() for the missing device, which uses device->bdev (NULL for missing device) to find if the device supports discard. Fix is to check if the device is missing before calling btrfs_trim_free_extents(). CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Filipe Manana Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/extent-tree.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -6034,6 +6034,9 @@ int btrfs_trim_fs(struct btrfs_fs_info * mutex_lock(&fs_info->fs_devices->device_list_mutex); devices = &fs_info->fs_devices->devices; list_for_each_entry(device, devices, dev_list) { + if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) + continue; + ret = btrfs_trim_free_extents(device, &group_trimmed); if (ret) { dev_failed++;