From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f207.google.com (mail-oi1-f207.google.com [209.85.167.207]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 650154A33ED for ; Wed, 15 Jul 2026 17:57:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784138271; cv=none; b=QuJo8Ww/szoQPkZf76i7xR44TurTVfC6KUnMkPOepQDNdMTl7FGMjxUqkt2SDVx3fyjTHRKi12XzAYwilzGo8oOQkShTqfR4zqc1y3rCxNmlpAXO5V4bLIis6Vo10WxDsQU2lwbt569OJZSrb9yyCEurKjOTQSAFoiOi7NxVe0I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784138271; c=relaxed/simple; bh=JBbo+zcU0pMtB9AcpSLYfzuPtvH4WBZMwwNJ3t2SMUY=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=c7g+YNfoFiUESHnd/rsm2zLaMOn80p5PyMLMONa4SHyaXKL76SK0SIVxbM0aphQNnmnURLdUWcFBC402ru6kGFxfFTfNlOfRc/EiyuSFKD8anYfoGt/uisXQSHq443Ga4X536KXc6blTPQIAmza8tKOOtdcEDGO7F1CgndaClYc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.167.207 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oi1-f207.google.com with SMTP id 5614622812f47-4a43d32fa9fso4610964b6e.2 for ; Wed, 15 Jul 2026 10:57:49 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784138268; x=1784743068; h=content-type:to:from:subject:message-id:in-reply-to:date :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=JKvb5+ZvVQsDXDQPm3ttQu83bZMGgTakUvAB7vEtebs=; b=RJejYOzgFNv5ZbCoTKZn7JDVqiUuvT7+gTRMtJRJw8+dw7SmjHOH45WwUBKXZtCv1j mEkfUVl/bFzCaVYT2YN1erT7Smgqt9E7JsXJFe7jH0x3AJ2zIXxwQF/zHOsAZBUF00X3 zQ6/I7oQbTeZGjKluOkEZ/IhudHg9L7P4pvXgZq6NmUHaPU/J1qF6SxFCMqlA8f5ofyX Vx4pyzGdQCi3u/xRfetnvZFab+IsTUyuWgU6RVZxkBppDwlpYv6FuNaoa6v93EZDS5ZW 9mePQVSR0ojvnWgrzHbq7MwD2AMBTJx+A8GUGvmXKCMXjCN3gb3/n7kOfOfj0RG0zdRX lwdA== X-Gm-Message-State: AOJu0YzfZKqOhgVrnPn2D0YCAXkI5M9avKOk50eVkYAYwT4+A6N7aY9W G7+YlMesrcoI34NzHP+2vED9saN0OgUQMCKR0ToHIe/YzwFdyejpKEeLaRfgpWidn6sdRmi+w9M k8RHgB71RB4JR+rw942/xu/IU0HmxWoqeRXOFGPW9cCmRKbJeAczWULEOU8Bf1A== Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:1246:b0:496:e0:a47b with SMTP id 5614622812f47-4a42af5f7b2mr10961710b6e.20.1784138268305; Wed, 15 Jul 2026 10:57:48 -0700 (PDT) Date: Wed, 15 Jul 2026 10:57:48 -0700 In-Reply-To: <66f7b39f.050a0220.46d20.0037.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a57ca1c.9d83364e.246513.0009.GAE@google.com> Subject: Forwarded: Re: [syzbot] [ext4?] possible deadlock in ext4_xattr_inode_lookup_create From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com. *** Subject: Re: [syzbot] [ext4?] possible deadlock in ext4_xattr_inode_lookup_create Author: koike@igalia.com #syz fix: ext4: lockdep: handle i_data_sem subclassing for special inodes On 9/28/24 4:43 AM, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 2b7275670032 Add linux-next specific files for 20240925 > git tree: linux-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=12fdd627980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=441f6022e7a2db73 > dashboard link: https://syzkaller.appspot.com/bug?extid=d91a6e2efb07bd3354e9 > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1771ca80580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=102e0907980000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/de8e955e430e/disk-2b727567.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/cdc30f0c4010/vmlinux-2b727567.xz > kernel image: https://storage.googleapis.com/syzbot-assets/5bce68c83e37/bzImage-2b727567.xz > mounted in repro: https://storage.googleapis.com/syzbot-assets/b35179829fb5/mount_0.gz > > The issue was bisected to: > > commit 1e9d62d252812575ded7c620d8fc67c32ff06c16 > Author: Jun Nie > Date: Tue Jan 3 01:45:16 2023 +0000 > > ext4: optimize ea_inode block expansion > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14edcaa9980000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=16edcaa9980000 > console output: https://syzkaller.appspot.com/x/log.txt?x=12edcaa9980000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+d91a6e2efb07bd3354e9@syzkaller.appspotmail.com > Fixes: 1e9d62d25281 ("ext4: optimize ea_inode block expansion") > > EXT4-fs: Ignoring removed nomblk_io_submit option > ====================================================== > WARNING: possible circular locking dependency detected > 6.11.0-next-20240925-syzkaller #0 Not tainted > ------------------------------------------------------ > syz-executor177/5387 is trying to acquire lock: > ffff888071dd97c8 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline] > ffff888071dd97c8 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}, at: ext4_xattr_inode_create fs/ext4/xattr.c:1514 [inline] > ffff888071dd97c8 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}, at: ext4_xattr_inode_lookup_create+0x1a31/0x1f20 fs/ext4/xattr.c:1596 > > but task is already holding lock: > ffff888071ddc7e0 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_truncate+0x994/0x11c0 fs/ext4/inode.c:4180 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #1 (&ei->i_data_sem/3){++++}-{3:3}: > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 > down_write+0x99/0x220 kernel/locking/rwsem.c:1577 > ext4_update_i_disksize fs/ext4/ext4.h:3398 [inline] > ext4_xattr_inode_write fs/ext4/xattr.c:1452 [inline] > ext4_xattr_inode_lookup_create+0x16b8/0x1f20 fs/ext4/xattr.c:1602 > ext4_xattr_ibody_set+0x214/0x730 fs/ext4/xattr.c:2269 > ext4_xattr_set_handle+0xba6/0x1580 fs/ext4/xattr.c:2446 > ext4_xattr_set+0x241/0x3d0 fs/ext4/xattr.c:2560 > __vfs_setxattr+0x468/0x4a0 fs/xattr.c:200 > __vfs_setxattr_noperm+0x12e/0x660 fs/xattr.c:234 > vfs_setxattr+0x221/0x430 fs/xattr.c:321 > do_setxattr fs/xattr.c:629 [inline] > path_setxattr+0x37e/0x4d0 fs/xattr.c:658 > __do_sys_setxattr fs/xattr.c:676 [inline] > __se_sys_setxattr fs/xattr.c:672 [inline] > __x64_sys_setxattr+0xbb/0xd0 fs/xattr.c:672 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > -> #0 (&ea_inode->i_rwsem#8/1){+.+.}-{3:3}: > check_prev_add kernel/locking/lockdep.c:3161 [inline] > check_prevs_add kernel/locking/lockdep.c:3280 [inline] > validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 > __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 > down_write+0x99/0x220 kernel/locking/rwsem.c:1577 > inode_lock include/linux/fs.h:815 [inline] > ext4_xattr_inode_create fs/ext4/xattr.c:1514 [inline] > ext4_xattr_inode_lookup_create+0x1a31/0x1f20 fs/ext4/xattr.c:1596 > ext4_xattr_block_set+0x274/0x3980 fs/ext4/xattr.c:1916 > ext4_xattr_move_to_block fs/ext4/xattr.c:2669 [inline] > ext4_xattr_make_inode_space fs/ext4/xattr.c:2744 [inline] > ext4_expand_extra_isize_ea+0x12d7/0x1cf0 fs/ext4/xattr.c:2836 > __ext4_expand_extra_isize+0x2fb/0x3e0 fs/ext4/inode.c:5831 > ext4_try_to_expand_extra_isize fs/ext4/inode.c:5874 [inline] > __ext4_mark_inode_dirty+0x524/0x880 fs/ext4/inode.c:5952 > ext4_ext_truncate+0x9f/0x2b0 fs/ext4/extents.c:4457 > ext4_truncate+0xa1b/0x11c0 fs/ext4/inode.c:4185 > ext4_evict_inode+0x90f/0xf50 fs/ext4/inode.c:263 > evict+0x4e8/0x9b0 fs/inode.c:806 > __dentry_kill+0x20d/0x630 fs/dcache.c:615 > dput+0x19f/0x2b0 fs/dcache.c:857 > do_renameat2+0xda1/0x13f0 fs/namei.c:5181 > __do_sys_renameat2 fs/namei.c:5213 [inline] > __se_sys_renameat2 fs/namei.c:5210 [inline] > __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5210 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > other info that might help us debug this: > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&ei->i_data_sem/3); > lock(&ea_inode->i_rwsem#8/1); > lock(&ei->i_data_sem/3); > lock(&ea_inode->i_rwsem#8/1); > > *** DEADLOCK *** > > 7 locks held by syz-executor177/5387: > #0: ffff88802da0e420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 > #1: ffff88802da0e730 (&type->s_vfs_rename_key){+.+.}-{3:3}, at: lock_rename fs/namei.c:3165 [inline] > #1: ffff88802da0e730 (&type->s_vfs_rename_key){+.+.}-{3:3}, at: do_renameat2+0x5cf/0x13f0 fs/namei.c:5114 > #2: ffff88807755f0f0 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline] > #2: ffff88807755f0f0 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: lock_two_directories+0x145/0x220 fs/namei.c:3131 > #3: ffff888071dd83f8 (&type->i_mutex_dir_key#3/5){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline] > #3: ffff888071dd83f8 (&type->i_mutex_dir_key#3/5){+.+.}-{3:3}, at: lock_two_directories+0x16f/0x220 fs/namei.c:3132 > #4: ffff88802da0e610 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1721 [inline] > #4: ffff88802da0e610 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1904 [inline] > #4: ffff88802da0e610 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x2f4/0xf50 fs/ext4/inode.c:217 > #5: ffff888071ddc7e0 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_truncate+0x994/0x11c0 fs/ext4/inode.c:4180 > #6: ffff888071ddc620 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:161 [inline] > #6: ffff888071ddc620 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5871 [inline] > #6: ffff888071ddc620 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x491/0x880 fs/ext4/inode.c:5952 > > stack backtrace: > CPU: 0 UID: 0 PID: 5387 Comm: syz-executor177 Not tainted 6.11.0-next-20240925-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 > Call Trace: > > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 > print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 > check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 > check_prev_add kernel/locking/lockdep.c:3161 [inline] > check_prevs_add kernel/locking/lockdep.c:3280 [inline] > validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 > __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 > down_write+0x99/0x220 kernel/locking/rwsem.c:1577 > inode_lock include/linux/fs.h:815 [inline] > ext4_xattr_inode_create fs/ext4/xattr.c:1514 [inline] > ext4_xattr_inode_lookup_create+0x1a31/0x1f20 fs/ext4/xattr.c:1596 > ext4_xattr_block_set+0x274/0x3980 fs/ext4/xattr.c:1916 > ext4_xattr_move_to_block fs/ext4/xattr.c:2669 [inline] > ext4_xattr_make_inode_space fs/ext4/xattr.c:2744 [inline] > ext4_expand_extra_isize_ea+0x12d7/0x1cf0 fs/ext4/xattr.c:2836 > __ext4_expand_extra_isize+0x2fb/0x3e0 fs/ext4/inode.c:5831 > ext4_try_to_expand_extra_isize fs/ext4/inode.c:5874 [inline] > __ext4_mark_inode_dirty+0x524/0x880 fs/ext4/inode.c:5952 > ext4_ext_truncate+0x9f/0x2b0 fs/ext4/extents.c:4457 > ext4_truncate+0xa1b/0x11c0 fs/ext4/inode.c:4185 > ext4_evict_inode+0x90f/0xf50 fs/ext4/inode.c:263 > evict+0x4e8/0x9b0 fs/inode.c:806 > __dentry_kill+0x20d/0x630 fs/dcache.c:615 > dput+0x19f/0x2b0 fs/dcache.c:857 > do_renameat2+0xda1/0x13f0 fs/namei.c:5181 > __do_sys_renameat2 fs/namei.c:5213 [inline] > __se_sys_renameat2 fs/namei.c:5210 [inline] > __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5210 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f9326d33469 > Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 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:00007ffdce15cbc8 EFLAGS: 00000246 ORIG_RAX: 000000000000013c > RAX: ffffffffffffffda RBX: 00007f9326d7c0a0 RCX: 00007f9326d33469 > RDX: 0000000000000005 RSI: 0000000020000080 RDI: 0000000000000006 > RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffdce15cc00 > R10: 00000000200000c0 R11: 0000000000000246 R12: 00007ffdce15cbec > R13: 0000000000000031 R14: 431bde82d7b634db R15: 00007ffdce15cc20 > > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > > If the report is already addressed, let syzbot know by replying with: > #syz fix: exact-commit-title > > If you want syzbot to run the reproducer, reply with: > #syz test: git://repo/address.git branch-or-commit-hash > If you attach or paste a git patch, syzbot will apply it before testing. > > If you want to overwrite report's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup