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=-8.7 required=3.0 tests=BAYES_00,FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,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 18431C433E7 for ; Tue, 13 Oct 2020 23:22:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D498C21D7B for ; Tue, 13 Oct 2020 23:22:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388927AbgJMXWL (ORCPT ); Tue, 13 Oct 2020 19:22:11 -0400 Received: from mail-il1-f200.google.com ([209.85.166.200]:45778 "EHLO mail-il1-f200.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388809AbgJMXWL (ORCPT ); Tue, 13 Oct 2020 19:22:11 -0400 Received: by mail-il1-f200.google.com with SMTP id b4so1075287ilf.12 for ; Tue, 13 Oct 2020 16:22:10 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:in-reply-to:message-id:subject :from:to; bh=CLuWVMOjTHLbVNABKCSg2IFm2uuzV5Q3xX78MVcxpa4=; b=c8Fvf3GXfxpbDNWKb1b4pEn+VD0paYEM54zugrBIhls3PRkAFHnn+1c5v2HZSXlZ3O WW6wL9htgYMD+bK9pwUXM+jOrTbeVKFlpTjF6Qo/2YOvl/INX+mLjzKilWKyriFHSjOb c5j5zfqEmBphoY8oo1nSTaqSrAKO8Uw4x1rSeUGeQKw9B/+agHPBxpiDvBAeTnX1lRns uR2cwEsPO2QS/54WiPCsYUYW1M4WMRkx9Nd1G5w51ahnvY8wUUTnk1Z1ylvs416d1kNr myQO3+CsGmrDj/YyN52iQocLL2MV42tj/O1pEvPIZWGz8Ssww0NaOJfh7jEDMqEAtvp6 LfEg== X-Gm-Message-State: AOAM5330DQUzMbFCKIbvimslfnJDP9WHP2Fs0KHu3XJ+ZDYmhT7zXzTW xtzTUHH6pPW6Af+6Ubpmmb3c28ssAoNI3YLqgM/QNreNN9Gc X-Google-Smtp-Source: ABdhPJytMsqmWbNomF8life4uIsoh57pgRfO8LWK7P/0il52Zr6aq3csqgwDl0EGu6aQpKwHDoshMH+2UFz2BT0T3chWMPkfCFqf MIME-Version: 1.0 X-Received: by 2002:a5d:9842:: with SMTP id p2mr850448ios.113.1602631330275; Tue, 13 Oct 2020 16:22:10 -0700 (PDT) Date: Tue, 13 Oct 2020 16:22:10 -0700 In-Reply-To: <157941.1602619974@warthog.procyon.org.uk> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000025a54905b195af3d@google.com> Subject: Re: KASAN: use-after-free Read in fscache_alloc_cookie From: syzbot To: dhowells@redhat.com, linux-cachefs@redhat.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: WARNING: proc registration bug in afs_manage_cell_work ------------[ cut here ]------------ proc_dir_entry 'afs/^]$[+%]0${' already registered WARNING: CPU: 0 PID: 8309 at fs/proc/generic.c:371 proc_register+0x34c/0x700 fs/proc/generic.c:371 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8309 Comm: kworker/0:4 Not tainted 5.9.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: afs afs_manage_cell_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fd lib/dump_stack.c:118 panic+0x382/0x7fb kernel/panic.c:231 __warn.cold+0x20/0x4b kernel/panic.c:600 report_bug+0x1bd/0x210 lib/bug.c:198 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234 exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536 RIP: 0010:proc_register+0x34c/0x700 fs/proc/generic.c:371 Code: df 48 89 f9 48 c1 e9 03 80 3c 01 00 0f 85 5d 03 00 00 48 8b 44 24 28 48 c7 c7 a0 62 9a 88 48 8b b0 d8 00 00 00 e8 46 03 5d ff <0f> 0b 48 c7 c7 e0 f6 1e 8a e8 36 df 3d 06 48 8b 4c 24 38 48 b8 00 RSP: 0018:ffffc90009dffac8 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff8880923a4480 RSI: ffffffff815f5a55 RDI: fffff520013bff4b RBP: ffff888088829b88 R08: 0000000000000001 R09: ffff8880ae4318e7 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880904699d8 R13: ffff8880931d3340 R14: dffffc0000000000 R15: 000000000000000a proc_mkdir_data+0x140/0x1a0 fs/proc/generic.c:487 proc_net_mkdir include/linux/proc_fs.h:201 [inline] afs_proc_cell_setup+0xb2/0x1f0 fs/afs/proc.c:619 afs_activate_cell fs/afs/cell.c:684 [inline] afs_manage_cell fs/afs/cell.c:768 [inline] afs_manage_cell_work+0x5b7/0x11c0 fs/afs/cell.c:832 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Kernel Offset: disabled Rebooting in 86400 seconds.. Tested on: commit: f8eb8d1c afs: Add tracing for cell refcount and active use.. git tree: git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git console output: https://syzkaller.appspot.com/x/log.txt?x=1414b0d8500000 kernel config: https://syzkaller.appspot.com/x/.config?x=302928762dfb5528 dashboard link: https://syzkaller.appspot.com/bug?extid=2d0585e5efcd43d113c2 compiler: gcc (GCC) 10.1.0-syz 20200507