From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f208.google.com (mail-il1-f208.google.com [209.85.166.208]) (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 A56CF18CC13 for ; Wed, 26 Nov 2025 23:09:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.208 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764198572; cv=none; b=U4wW85oTL9Plsux84TOxSZy/kLN74Mx9pQtg7rUoeGAdluN+Q/qzJIiu3G7BcWYO0Hclrm0ZmQ9NS08ta8zd70YGrBqnLBHqw/bjfNONpqRoCgonIbLGuls+3HEqzO4BwS5eQIKXP7wPTK+k/gy6ROPSy0nLKi2YkHQNk6P21qo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764198572; c=relaxed/simple; bh=TsTxKTC25QO4tsGYLpDRzqI10NdgAACO+ajctYtRLjA=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=mh1NqUHg2336mz8Vn/A5uy2zB80hlYxFuIFcgarM7hoYulscDCqgOY2NL/czj809e+7JkEhrsMZnA2ziMyHe/sRIsMCpy12ylR12Zkq16XjODPoE45N/Y0y0yGANA9e9Fp83YPZmybN7/5w4KPay1iWz8ZBxT2FWoutc3X5MFMA= 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=209.85.166.208 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-il1-f208.google.com with SMTP id e9e14a558f8ab-435a04dace1so2939805ab.0 for ; Wed, 26 Nov 2025 15:09:30 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764198570; x=1764803370; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=R1M0Z958mw30CkNu259X+iv6Lr1kHZiaRf15eYWXL5M=; b=v8k8dfLh5zqwYOCwpEdUnN5Td7bBSRpRXVg4vMa+lb1rqvJBIq54qXW6y4TMW1DD3P XwFaNiH7XUBiPRdKGr7Gkn4f079TA2k2J4R/wDhsKjSunMv4giVK7MQtjT3SVgExO7IM zd89uysZVLTZMidSJM9eB1kYzWDkdZE2AgIaPLrK0xXtFiSusou9d4heNeSjyhDfuyc1 GT6FkAwkyup3JMUGUTnA1BGmQp8I0Ae7rT5Fl8G/BqoUkVtBV2QJD/raECQXyYq3HxBO z2l5SOidWf5ZKVxsH0nKG8zA/dnIariZJhMz1azGF06YCNylWqI6qEEHQVhMKRlnslJX Gp+Q== X-Forwarded-Encrypted: i=1; AJvYcCXktvVHF3AxcslZl9X3UaRhtnBDDCB8yjPqOf/ClynTzPqKsMtQ0aZc4sM1MQHMJ8epYx5Y54A4JqHUkPg=@vger.kernel.org X-Gm-Message-State: AOJu0Yz1/RC0Yk9Ob9sbEK53QttdfvQdy7FYoEAJ49G2xPDycmkmmocV 8dlbbwB5QVqCLNk6dL/IxxkGcY8pmoX+5L5MGqofuG+tabg2ZLKCiNzwVIy+woCxw5S7K3q2DBI 6LqFbu8eA0OcuIvQcVEcNkYFS2RSgR+QjNKsbHg5uWagWXODjG86efKLm8vs= X-Google-Smtp-Source: AGHT+IHDHm0qfW9REafx484SpeW8eYNBReRQ9ygpOqwMQIuJonbxK1oyrfsI/CuebMfx7e0l7wzW7tIy1Pi1EI3yAdX90Xr8wxZZ Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1986:b0:435:a467:b324 with SMTP id e9e14a558f8ab-435b9862f5bmr166492555ab.17.1764198569809; Wed, 26 Nov 2025 15:09:29 -0800 (PST) Date: Wed, 26 Nov 2025 15:09:29 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <692788a9.a70a0220.d98e3.00e3.GAE@google.com> Subject: [syzbot] [ext4?] possible deadlock in evict (4) From: syzbot To: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tytso@mit.edu Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 30f09200cc4a Merge tag 'arm64-fixes' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15adee92580000 kernel config: https://syzkaller.appspot.com/x/.config?x=884a6f5f4d7949fd dashboard link: https://syzkaller.appspot.com/bug?extid=a30a00d3e694e4fa1315 compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/7eaf4b9ef160/disk-30f09200.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/ab7dc38c62bf/vmlinux-30f09200.xz kernel image: https://storage.googleapis.com/syzbot-assets/85299a9adb30/bzImage-30f09200.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a30a00d3e694e4fa1315@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.5384/26557 is trying to acquire lock: ffff88805de42610 (sb_internal){.+.+}-{0:0}, at: evict+0x3e6/0x920 fs/inode.c:810 but task is already holding lock: ffff88807c0ccb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_write fs/ext4/ext4.h:1808 [inline] ffff88807c0ccb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x39c/0x1ee0 fs/ext4/migrate.c:438 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sbi->s_writepages_rwsem){++++}-{0:0}: percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1796 [inline] ext4_writepages+0x224/0x7d0 fs/ext4/inode.c:3024 do_writepages+0x27a/0x600 mm/page-writeback.c:2604 __writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1719 writeback_single_inode+0x2bc/0x550 fs/fs-writeback.c:1840 write_inode_now+0x170/0x1e0 fs/fs-writeback.c:2903 iput_final fs/inode.c:1901 [inline] iput.part.0+0x487/0xb00 fs/inode.c:1966 iput+0x35/0x40 fs/inode.c:1929 ext4_xattr_block_set+0x67c/0x3650 fs/ext4/xattr.c:2199 ext4_xattr_move_to_block fs/ext4/xattr.c:2664 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2739 [inline] ext4_expand_extra_isize_ea+0x1442/0x1ab0 fs/ext4/xattr.c:2827 __ext4_expand_extra_isize+0x346/0x480 fs/ext4/inode.c:6364 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6407 [inline] __ext4_mark_inode_dirty+0x544/0x870 fs/ext4/inode.c:6485 ext4_evict_inode+0x74e/0x18e0 fs/ext4/inode.c:254 evict+0x3e6/0x920 fs/inode.c:810 iput_final fs/inode.c:1914 [inline] iput.part.0+0x6a9/0xb00 fs/inode.c:1966 iput+0x35/0x40 fs/inode.c:1929 ext4_orphan_cleanup+0x731/0x11e0 fs/ext4/orphan.c:470 __ext4_fill_super fs/ext4/super.c:5617 [inline] ext4_fill_super+0x8db7/0xaf70 fs/ext4/super.c:5736 get_tree_bdev_flags+0x38c/0x620 fs/super.c:1698 vfs_get_tree+0x8e/0x340 fs/super.c:1758 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3642 [inline] do_new_mount fs/namespace.c:3718 [inline] path_mount+0x7b9/0x23a0 fs/namespace.c:4028 do_mount fs/namespace.c:4041 [inline] __do_sys_mount fs/namespace.c:4229 [inline] __se_sys_mount fs/namespace.c:4206 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4206 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (sb_internal){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs.h:1916 [inline] sb_start_intwrite include/linux/fs.h:2099 [inline] ext4_evict_inode+0xe3e/0x18e0 fs/ext4/inode.c:215 evict+0x3e6/0x920 fs/inode.c:810 iput_final fs/inode.c:1914 [inline] iput.part.0+0x6a9/0xb00 fs/inode.c:1966 iput+0x35/0x40 fs/inode.c:1929 ext4_ext_migrate+0xc6f/0x1ee0 fs/ext4/migrate.c:588 __ext4_ioctl+0x3178/0x4410 fs/ext4/ioctl.c:1694 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sbi->s_writepages_rwsem); lock(sb_internal); lock(&sbi->s_writepages_rwsem); rlock(sb_internal); *** DEADLOCK *** 3 locks held by syz.4.5384/26557: #0: ffff88805de42420 (sb_writers#4){.+.+}-{0:0}, at: __ext4_ioctl+0x3146/0x4410 fs/ext4/ioctl.c:1684 #1: ffff888045cd0d70 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff888045cd0d70 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: __ext4_ioctl+0x3170/0x4410 fs/ext4/ioctl.c:1693 #2: ffff88807c0ccb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_write fs/ext4/ext4.h:1808 [inline] #2: ffff88807c0ccb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x39c/0x1ee0 fs/ext4/migrate.c:438 stack backtrace: CPU: 0 UID: 0 PID: 26557 Comm: syz.4.5384 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2043 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs.h:1916 [inline] sb_start_intwrite include/linux/fs.h:2099 [inline] ext4_evict_inode+0xe3e/0x18e0 fs/ext4/inode.c:215 evict+0x3e6/0x920 fs/inode.c:810 iput_final fs/inode.c:1914 [inline] iput.part.0+0x6a9/0xb00 fs/inode.c:1966 iput+0x35/0x40 fs/inode.c:1929 ext4_ext_migrate+0xc6f/0x1ee0 fs/ext4/migrate.c:588 __ext4_ioctl+0x3178/0x4410 fs/ext4/ioctl.c:1694 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc21398f749 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc2148be038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc213be5fa0 RCX: 00007fc21398f749 RDX: 0000000000000000 RSI: 0000000000006609 RDI: 0000000000000004 RBP: 00007fc213a13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc213be6038 R14: 00007fc213be5fa0 R15: 00007ffc7410fa88 --- 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. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title 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