From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f79.google.com (mail-ot1-f79.google.com [209.85.210.79]) (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 A75F036B07C for ; Sun, 12 Jul 2026 18:49:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783882182; cv=none; b=kYXfqv0N3pbCj4WWVrfV3U0tPu6YTgcSxGgMUZycraK5upVA1yE75dMwQ2oXUvNuxseBKhx91TzS1mugo1gZa7tXL52oDwDkc2bD5WN4b3HJ370I6vRmB+z+lLWe6vvkq0IIx/VN1BeVWqaGKtPlwVSi2ogAM/lmKtwni3samIU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783882182; c=relaxed/simple; bh=U/Nn4wHvOsW3xC6GnOx/hZfKlEwVZiFYmxvm8SKCmWQ=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=tlbB4ZT9mekg2vDSEQ1FAdEh3OZz8rPkaN2aPv1HFz7CsttNRAazw6+g1iC9UpuxGOEyJG8cblCHLxaAt2AkEKLSb6SRewfAOTbU8QV6HWdxM4FjwyQquxBbr8wRfSLBRC9kIqUPLqRGDmJNErrEHY2yZ/FlzEs8QbslxlEKXtU= 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=209.85.210.79 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-ot1-f79.google.com with SMTP id 46e09a7af769-7e9fdc2870fso1451886a34.2 for ; Sun, 12 Jul 2026 11:49:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783882179; x=1784486979; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=zv+UWdhAnDCA2XUrVR4E7pUtYoXyHbuwGTRef4D6ZWM=; b=eSmUGAXchS1UR5Yx7Ex9Rv3TghVoCsNcLRRPoavZNugM9Dx9DEhLXlkTJ2BK1CDH8p HlGqc+i4dVzKn/JcHbKg3ujnpTzFFiAPjg2buH0v6Q+iOgDVN4KldtTFOrKvzuqrTF0E ulY/SUQDGy3lovI5LRqslISGsiyTTKlpZ9T82hX43utOf96F25VPkoiaaDCvMdNvxUFn NzASoPqPSUILezRjoQmjIEIk1O6HqdOFat697L3mnyVD1dqtAwsPufNi4/MCRN8ikqEc izCl7rYl7R8OSWyFlTo/NWkLsXTkCvIlaL5xeoPDo1KU9neTeJvEohxqvPRu2hiOzjxy M+fQ== X-Forwarded-Encrypted: i=1; AFNElJ82NOtKTE3NHquVnPNu9bVH1LQmhR1C5mO/J1pD4HPGAB0lAR79DrY6Dfk2PPtkzh7fzq/8OkjdgVaKoFc=@vger.kernel.org X-Gm-Message-State: AOJu0YwXR1Eb2R66VAtDXWNxtXU2sCKCv1ZScDPoVLSroZylnj3ViGfD +YRfTsS0DojlG5KhDPP0W4hzmkxcwVENTP4HaTcqZ68XOPkKiBFomGH0NptXPJ/L5YESpKE3jwc G6pCAa9Rzqe1YdzjNyFFt5S6TQUBAkTnwIwNs3PH6LsqwQKNXMfPrWSJpSAw= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:3507:b0:496:b7c:23a6 with SMTP id 5614622812f47-4a42afafb7fmr4514609b6e.38.1783882179745; Sun, 12 Jul 2026 11:49:39 -0700 (PDT) Date: Sun, 12 Jul 2026 11:49:39 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a53e1c3.278cdcd2.e885.001f.GAE@google.com> Subject: [syzbot] [xfs?] possible deadlock in xfs_dquot_disk_alloc (2) From: syzbot To: cem@kernel.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 0e35b9b6ec0f Merge tag 'mm-hotfixes-stable-2026-07-06-17-4.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=134d6739580000 kernel config: https://syzkaller.appspot.com/x/.config?x=20c9876b0f77b546 dashboard link: https://syzkaller.appspot.com/bug?extid=59178abfeb0ea3f0ab20 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-0e35b9b6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/2a17ca6db8f5/vmlinux-0e35b9b6.xz kernel image: https://storage.googleapis.com/syzbot-assets/c885024dccba/bzImage-0e35b9b6.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+59178abfeb0ea3f0ab20@syzkaller.appspotmail.com loop0: detected capacity change from 0 to 32768 XFS (loop0): Mounting V5 Filesystem bfdc47fc-10d8-4eed-a562-11a831b3f791 XFS (loop0): Ending clean mount XFS (loop0): Quotacheck needed: Please wait. XFS (loop0): Quotacheck: Done. loop0: detected capacity change from 32768 to 0 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.0/5333 is trying to acquire lock: ffffffff8ec86c80 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:317 [inline] ffffffff8ec86c80 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4565 [inline] ffffffff8ec86c80 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4925 [inline] ffffffff8ec86c80 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_noprof+0x64/0x5f0 mm/slub.c:4959 but task is already holding lock: ffff88801f853b00 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_dquot_disk_alloc+0x2cf/0xae0 fs/xfs/xfs_dquot.c:363 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&xfs_nondir_ilock_class){++++}-{4:4}: down_write_nested+0x9d/0x210 kernel/locking/rwsem.c:1757 xfs_reclaim_inode fs/xfs/xfs_icache.c:1046 [inline] xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1738 [inline] xfs_icwalk_ag+0x12b7/0x1980 fs/xfs/xfs_icache.c:1820 xfs_icwalk fs/xfs/xfs_icache.c:1868 [inline] xfs_reclaim_inodes_nr+0x1e5/0x260 fs/xfs/xfs_icache.c:1112 super_cache_scan+0x40e/0x4a0 fs/super.c:229 do_shrink_slab+0x6d0/0x10e0 mm/shrinker.c:443 shrink_slab+0xea4/0x1220 mm/shrinker.c:674 shrink_one+0x2a2/0x730 mm/vmscan.c:5026 shrink_many mm/vmscan.c:5087 [inline] lru_gen_shrink_node mm/vmscan.c:5165 [inline] shrink_node+0x3303/0x3b60 mm/vmscan.c:6154 kswapd_shrink_node mm/vmscan.c:7008 [inline] balance_pgdat mm/vmscan.c:7186 [inline] kswapd+0x17b6/0x31c0 mm/vmscan.c:7462 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #0 (fs_reclaim){+.+.}-{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+0x1520/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __fs_reclaim_acquire mm/page_alloc.c:4329 [inline] fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4343 might_alloc include/linux/sched/mm.h:317 [inline] slab_pre_alloc_hook mm/slub.c:4565 [inline] slab_alloc_node mm/slub.c:4925 [inline] kmem_cache_alloc_noprof+0x64/0x5f0 mm/slub.c:4959 xfs_buf_item_init+0x6a/0x6e0 fs/xfs/xfs_buf_item.c:872 _xfs_trans_bjoin+0x46/0x110 fs/xfs/xfs_trans_buf.c:75 xfs_trans_bjoin+0x2e/0x220 fs/xfs/xfs_trans_buf.c:102 xfs_defer_restore_resources+0x32f/0x7c0 fs/xfs/libxfs/xfs_defer.c:451 xfs_defer_trans_roll+0x1a9/0x5e0 fs/xfs/libxfs/xfs_defer.c:481 xfs_defer_finish_noroll+0x844/0x1320 fs/xfs/libxfs/xfs_defer.c:688 xfs_trans_commit+0x10b/0x1c0 fs/xfs/xfs_trans.c:919 xfs_dquot_disk_alloc+0x7a2/0xae0 fs/xfs/xfs_dquot.c:435 xfs_qm_dqread+0xfe/0x520 fs/xfs/xfs_dquot.c:720 xfs_qm_dqget+0x18a/0x3d0 fs/xfs/xfs_dquot.c:922 xfs_qm_vop_dqalloc+0x472/0xaa0 fs/xfs/xfs_qm.c:1887 xfs_setattr_nonsize+0x3a1/0xca0 fs/xfs/xfs_iops.c:831 xfs_vn_setattr+0x29e/0x310 fs/xfs/xfs_iops.c:1161 notify_change+0xbba/0xea0 fs/attr.c:556 chown_common+0x41c/0x630 fs/open.c:776 vfs_fchown fs/open.c:841 [inline] ksys_fchown+0xe9/0x160 fs/open.c:853 __do_sys_fchown fs/open.c:858 [inline] __se_sys_fchown fs/open.c:856 [inline] __x64_sys_fchown+0x7a/0x90 fs/open.c:856 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 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(&xfs_nondir_ilock_class); lock(fs_reclaim); lock(&xfs_nondir_ilock_class); lock(fs_reclaim); *** DEADLOCK *** 4 locks held by syz.0.0/5333: #0: ffff888042324450 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x60/0x200 fs/namespace.c:538 #1: ffff88801f8552d0 (&inode->i_sb->s_type->i_mutex_dir_key){++++}-{4:4}, at: inode_lock_killable include/linux/fs.h:1029 [inline] #1: ffff88801f8552d0 (&inode->i_sb->s_type->i_mutex_dir_key){++++}-{4:4}, at: chown_common+0x313/0x630 fs/open.c:764 #2: ffff888042324640 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc+0xcf/0x990 fs/xfs/xfs_trans.c:254 #3: ffff88801f853b00 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_dquot_disk_alloc+0x2cf/0xae0 fs/xfs/xfs_dquot.c:363 stack backtrace: CPU: 0 UID: 0 PID: 5333 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 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+0x1520/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __fs_reclaim_acquire mm/page_alloc.c:4329 [inline] fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4343 might_alloc include/linux/sched/mm.h:317 [inline] slab_pre_alloc_hook mm/slub.c:4565 [inline] slab_alloc_node mm/slub.c:4925 [inline] kmem_cache_alloc_noprof+0x64/0x5f0 mm/slub.c:4959 xfs_buf_item_init+0x6a/0x6e0 fs/xfs/xfs_buf_item.c:872 _xfs_trans_bjoin+0x46/0x110 fs/xfs/xfs_trans_buf.c:75 xfs_trans_bjoin+0x2e/0x220 fs/xfs/xfs_trans_buf.c:102 xfs_defer_restore_resources+0x32f/0x7c0 fs/xfs/libxfs/xfs_defer.c:451 xfs_defer_trans_roll+0x1a9/0x5e0 fs/xfs/libxfs/xfs_defer.c:481 xfs_defer_finish_noroll+0x844/0x1320 fs/xfs/libxfs/xfs_defer.c:688 xfs_trans_commit+0x10b/0x1c0 fs/xfs/xfs_trans.c:919 xfs_dquot_disk_alloc+0x7a2/0xae0 fs/xfs/xfs_dquot.c:435 xfs_qm_dqread+0xfe/0x520 fs/xfs/xfs_dquot.c:720 xfs_qm_dqget+0x18a/0x3d0 fs/xfs/xfs_dquot.c:922 xfs_qm_vop_dqalloc+0x472/0xaa0 fs/xfs/xfs_qm.c:1887 xfs_setattr_nonsize+0x3a1/0xca0 fs/xfs/xfs_iops.c:831 xfs_vn_setattr+0x29e/0x310 fs/xfs/xfs_iops.c:1161 notify_change+0xbba/0xea0 fs/attr.c:556 chown_common+0x41c/0x630 fs/open.c:776 vfs_fchown fs/open.c:841 [inline] ksys_fchown+0xe9/0x160 fs/open.c:853 __do_sys_fchown fs/open.c:858 [inline] __se_sys_fchown fs/open.c:856 [inline] __x64_sys_fchown+0x7a/0x90 fs/open.c:856 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0044f9de59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0045e1afe8 EFLAGS: 00000246 ORIG_RAX: 000000000000005d RAX: ffffffffffffffda RBX: 00007f0045225fa0 RCX: 00007f0044f9de59 RDX: 000000000000000a RSI: 000000003a736e6f RDI: 0000000000000006 RBP: 00007f0045033e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0045226038 R14: 00007f0045225fa0 R15: 00007fff82a814a8 --- 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