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 259C6C00140 for ; Mon, 8 Aug 2022 11:26:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242824AbiHHL0S (ORCPT ); Mon, 8 Aug 2022 07:26:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234627AbiHHL0P (ORCPT ); Mon, 8 Aug 2022 07:26:15 -0400 Received: from mail-il1-f198.google.com (mail-il1-f198.google.com [209.85.166.198]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0783E0A5 for ; Mon, 8 Aug 2022 04:26:14 -0700 (PDT) Received: by mail-il1-f198.google.com with SMTP id s5-20020a056e02216500b002dde8b02f62so6388663ilv.15 for ; Mon, 08 Aug 2022 04:26:14 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc; bh=3irFrXv3REG5wxAgtft4NjnGiayOela6WnpI7Xdmj6g=; b=M+NIenhiXcijVzyuziBFPMojt/tj1OY6XjDJ+dyvKE5lFPh3wFnlHwEHcLXoQp46sR 8y5KZdSGJZqAteSFIy6FU5FNg4R4ePAFtl3rHQYD0YfzVvGPo5gxEqZjIRvNFpmgGWqI zs2+KeWN4oVXzUNkbYMY9PhAoqk76vcukFCgmo8gbVqqi0KRBM/+eXbfwZhfdByIv1rF lQOI2PUjFGHpNTbFAVxowyQYD9uwP/RktDH08J7qRZ6/TVr5bYH1hgfVte5w8sBdgBAa tEI67rStUeCWryA4t6yJn3VjhZYK9lk5jQ5VO/cjMjWgnJfYwtt+A2iso9IZN/415moV J2vw== X-Gm-Message-State: ACgBeo3KRfSlL0l7R99xxXgPoVMJPc3lCsVXe4b309iRSCKP+Bv9P7GD jyfGuKYVfzRAVIo6iuf8mn9O2n1MpmV51tWRcyj5lx7AL0fB X-Google-Smtp-Source: AA6agR6F79tRsviGVjwhaMnqzpQ1e1VI1Z2hVH1Hxle9npvayNABg5SDvghFbUEV+IgcpkwQ1yt93kNVbPJMD2kegK47xh0rqvMy MIME-Version: 1.0 X-Received: by 2002:a05:6638:300e:b0:335:c73c:3d25 with SMTP id r14-20020a056638300e00b00335c73c3d25mr7911971jak.77.1659957974355; Mon, 08 Aug 2022 04:26:14 -0700 (PDT) Date: Mon, 08 Aug 2022 04:26:14 -0700 In-Reply-To: <20220808111439.2119-1-hdanton@sina.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000067595b05e5b9154f@google.com> Subject: Re: [syzbot] possible deadlock in ext4_xattr_get From: syzbot To: hdanton@sina.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: possible deadlock in ext4_xattr_get loop0: detected capacity change from 0 to 512 EXT4-fs (loop0): mounted filesystem without journal. Quota mode: none. ====================================================== WARNING: possible circular locking dependency detected 5.19.0-rc4-next-20220628-syzkaller-dirty #0 Not tainted ------------------------------------------------------ syz-executor.0/4081 is trying to acquire lock: ffff888073393cf8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_get+0x14e/0xa10 fs/ext4/xattr.c:650 but task is already holding lock: ffff888073394030 (&ea_inode->i_rwsem#9/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:761 [inline] ffff888073394030 (&ea_inode->i_rwsem#9/1){+.+.}-{3:3}, at: chown_common+0x364/0x710 fs/open.c:727 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&ea_inode->i_rwsem#9/1){+.+.}-{3:3}: down_write+0x90/0x150 kernel/locking/rwsem.c:1542 inode_lock include/linux/fs.h:761 [inline] ext4_xattr_inode_write fs/ext4/xattr.c:1391 [inline] ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1529 [inline] ext4_xattr_set_entry+0x2ec5/0x3800 fs/ext4/xattr.c:1653 ext4_xattr_ibody_set+0x78/0x2b0 fs/ext4/xattr.c:2206 ext4_xattr_set_handle+0x964/0x1500 fs/ext4/xattr.c:2363 ext4_xattr_set+0x13a/0x340 fs/ext4/xattr.c:2476 __vfs_setxattr+0x115/0x180 fs/xattr.c:182 __vfs_setxattr_noperm+0x125/0x5f0 fs/xattr.c:216 __vfs_setxattr_locked+0x1cf/0x260 fs/xattr.c:277 vfs_setxattr+0x13f/0x330 fs/xattr.c:303 setxattr+0x146/0x160 fs/xattr.c:611 path_setxattr+0x197/0x1c0 fs/xattr.c:630 __do_sys_setxattr fs/xattr.c:646 [inline] __se_sys_setxattr fs/xattr.c:642 [inline] __x64_sys_setxattr+0xc0/0x160 fs/xattr.c:642 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> #0 (&ei->xattr_sem){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x2abe/0x5660 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630 down_read+0x98/0x440 kernel/locking/rwsem.c:1489 ext4_xattr_get+0x14e/0xa10 fs/ext4/xattr.c:650 __vfs_getxattr+0xd9/0x140 fs/xattr.c:401 cap_inode_need_killpriv+0x3c/0x60 security/commoncap.c:301 security_inode_need_killpriv+0x40/0x90 security/security.c:1420 notify_change+0x6e7/0x1440 fs/attr.c:351 chown_common+0x61b/0x710 fs/open.c:734 do_fchownat+0x126/0x1e0 fs/open.c:765 __do_sys_fchownat fs/open.c:780 [inline] __se_sys_fchownat fs/open.c:777 [inline] __x64_sys_fchownat+0xba/0x150 fs/open.c:777 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ea_inode->i_rwsem#9/1); lock(&ei->xattr_sem); lock(&ea_inode->i_rwsem#9/1); lock(&ei->xattr_sem); *** DEADLOCK *** 2 locks held by syz-executor.0/4081: #0: ffff88807a612460 (sb_writers#4){.+.+}-{0:0}, at: do_fchownat+0x101/0x1e0 fs/open.c:762 #1: ffff888073394030 (&ea_inode->i_rwsem#9/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:761 [inline] #1: ffff888073394030 (&ea_inode->i_rwsem#9/1){+.+.}-{3:3}, at: chown_common+0x364/0x710 fs/open.c:727 stack backtrace: CPU: 0 PID: 4081 Comm: syz-executor.0 Not tainted 5.19.0-rc4-next-20220628-syzkaller-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x2abe/0x5660 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630 down_read+0x98/0x440 kernel/locking/rwsem.c:1489 ext4_xattr_get+0x14e/0xa10 fs/ext4/xattr.c:650 __vfs_getxattr+0xd9/0x140 fs/xattr.c:401 cap_inode_need_killpriv+0x3c/0x60 security/commoncap.c:301 security_inode_need_killpriv+0x40/0x90 security/security.c:1420 notify_change+0x6e7/0x1440 fs/attr.c:351 chown_common+0x61b/0x710 fs/open.c:734 do_fchownat+0x126/0x1e0 fs/open.c:765 __do_sys_fchownat fs/open.c:780 [inline] __se_sys_fchownat fs/open.c:777 [inline] __x64_sys_fchownat+0xba/0x150 fs/open.c:777 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7febbbc89209 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007febbcdc0168 EFLAGS: 00000246 ORIG_RAX: 0000000000000104 RAX: ffffffffffffffda RBX: 00007febbbd9bf60 RCX: 00007febbbc89209 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000005 RBP: 00007febbbce3161 R08: 0000000000001000 R09: 0000000000000000 R10: 000000000000ee01 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd5bc171ff R14: 00007febbcdc0300 R15: 0000000000022000 Tested on: commit: cb71b93c Add linux-next specific files for 20220628 git tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git console output: https://syzkaller.appspot.com/x/log.txt?x=13ec5671080000 kernel config: https://syzkaller.appspot.com/x/.config?x=badbc1adb2d582eb dashboard link: https://syzkaller.appspot.com/bug?extid=62120febbd1ee3c3c860 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 patch: https://syzkaller.appspot.com/x/patch.diff?x=162cf612080000