From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f206.google.com (mail-il1-f206.google.com [209.85.166.206]) (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 5DDAF338918 for ; Thu, 30 Oct 2025 09:00:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.206 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761814826; cv=none; b=YiRVIG8G7ZAZgYI2IglzI38L9qn/pwOmeUD5jl6gUZ6zSs1oEFrT1y2wVr7q8nBGEZj0ApJALKxOj9SLHy2AQmCl4/koSxsrvxeY3jk35AD6ac3qX66jk72QD7WyJwFKYpTlb/Gzbc0T9ZdwVbD59ZbP/+vcmkvLK9bJAPieA8U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761814826; c=relaxed/simple; bh=d5w1kU9irqg9Ll6oc5Y7p+6aUVP8DNbn7SY7qYCqWus=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=srSPcXa9hPTthgy8cXeh987PKVW1D7/LZXoB+7rni6qYFAqObupIez0FbpahT5cz+Icy1hN0itrSjz3Ov5jjeWcg8zpyTkx/zjwTs9IO8k+6zuvct1CpUrFQ/+qolsXaI1MPltHieaK/6Uqv4sTBwa/LMejNEbVdl4ZmUuDoslA= 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=209.85.166.206 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-f206.google.com with SMTP id e9e14a558f8ab-430b0adb3e2so12281075ab.0 for ; Thu, 30 Oct 2025 02:00:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1761814823; x=1762419623; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=oAXnFKVGkjCBGElDSK9+UPI3E+qrPmrN+/Ky3nzJInU=; b=rJerqka8Ve4dcziM281mgLJxc5WYDXIsN1AW9YtpL8ZhVdQJBoMUFk2fbaVc4tFfu8 Q4Q98rHmvfqEqvDk0bRFaz3ysi9ifl8Q9AUZOeCyyWaSNsSNSDAi8GCXxKi8VxecD98I ZP89w2SO+WNKcahCOwnBuD+zqV9vyow2b85DSoZYRSKZ1dspCvnLIbUT8JbjYC21iJ3c jS6+ZdvnHUpGVqmroRB49MsP7pWWQICcPIhxdIr43vGVxXJi2FQKk154qM/qQMlbDUi9 TkSxWdhGGy4+s7YmTJrtiQJt+ikh7nCTWP3+RC+A9a4R7GrNOrBxIneBRWYsc3J+y+VZ mWpQ== X-Forwarded-Encrypted: i=1; AJvYcCWTZ7NgzyVPojN54zwsdyosGQksTQxODNqvZhsm61gnjwasji9wdFJIfo8dE//V/L+C+DA49lZpnquejw==@vger.kernel.org X-Gm-Message-State: AOJu0YwzH9fCG/Y6tx8Ht7EVNMVOteAgv6vHFoiWw9tYtGiDH+dDTF8Q xIOtcAJsFh8nVfAZqvkEKiSQ25KbTz/A5vFSF2ra7bfZdkHjegisWe80Alf9zwVRIDojskVyGoN DwXpWtUSFzGtk7+6OdoTXjJ1HDIaszdw4Ut1lwN82gnH7iexamV99pxn/ZNw= X-Google-Smtp-Source: AGHT+IG1QRW9boT2a3Fkq1fUjCGza5c6f1ooy4dnHlmKtFFzp1OnU0W8pMbSZuggZ0TRb2MrkFZOTsVYkUL7/2XgXXRzF406b5u6 Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1c23:b0:430:b2a8:a9eb with SMTP id e9e14a558f8ab-433011d6fcbmr35273825ab.1.1761814823515; Thu, 30 Oct 2025 02:00:23 -0700 (PDT) Date: Thu, 30 Oct 2025 02:00:23 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69032927.050a0220.32483.022a.GAE@google.com> Subject: [syzbot] [btrfs] possible deadlock in page_cache_ra_unbounded (3) From: syzbot To: akpm@linux-foundation.org, clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, willy@infradead.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 72761a7e3122 Merge tag 'driver-core-6.18-rc3' of git://git.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=123dee7c580000 kernel config: https://syzkaller.appspot.com/x/.config?x=8345ce4ce316ca28 dashboard link: https://syzkaller.appspot.com/bug?extid=d7230f03206380ea0908 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/733feb854771/disk-72761a7e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/94891a491db1/vmlinux-72761a7e.xz kernel image: https://storage.googleapis.com/syzbot-assets/1dc1e26ee843/bzImage-72761a7e.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d7230f03206380ea0908@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.7.719/14515 is trying to acquire lock: ffff88805d893bd8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] ffff88805d893bd8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: page_cache_ra_unbounded+0x1a3/0x8e0 mm/readahead.c:233 but task is already holding lock: ffff88813ff74238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_fop_readdir+0x267/0x870 fs/kernfs/dir.c:1893 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&root->kernfs_rwsem){++++}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_write+0x3a/0x50 kernel/locking/rwsem.c:1590 kernfs_add_one+0x41/0x520 fs/kernfs/dir.c:791 kernfs_create_dir_ns+0xde/0x130 fs/kernfs/dir.c:1093 sysfs_create_dir_ns+0x123/0x280 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x5a5/0xb50 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_init_and_add+0x125/0x190 lib/kobject.c:457 btrfs_sysfs_add_qgroups+0x111/0x2b0 fs/btrfs/sysfs.c:2645 btrfs_quota_enable+0x25d/0x2920 fs/btrfs/qgroup.c:1022 btrfs_ioctl_quota_ctl+0x186/0x1c0 fs/btrfs/ioctl.c:3667 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&fs_info->qgroup_ioctl_lock){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547 btrfs_quota_enable+0x29c/0x2920 fs/btrfs/qgroup.c:1051 btrfs_ioctl_quota_ctl+0x186/0x1c0 fs/btrfs/ioctl.c:3667 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (btrfs_trans_num_extwriters){++++}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 join_transaction+0x1a4/0xca0 fs/btrfs/transaction.c:321 start_transaction+0x6b6/0x1620 fs/btrfs/transaction.c:705 btrfs_dirty_inode+0x9f/0x190 fs/btrfs/inode.c:6270 inode_update_time fs/inode.c:2117 [inline] touch_atime+0x2f9/0x6d0 fs/inode.c:2190 file_accessed include/linux/fs.h:2673 [inline] filemap_read+0x100b/0x11a0 mm/filemap.c:2820 __kernel_read+0x4d8/0x970 fs/read_write.c:530 integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:480 [inline] ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline] ima_calc_file_hash+0x86a/0x1700 security/integrity/ima/ima_crypto.c:568 ima_collect_measurement+0x42e/0x900 security/integrity/ima/ima_api.c:293 process_measurement+0x112d/0x1a40 security/integrity/ima/ima_main.c:405 ima_file_check+0xd7/0x120 security/integrity/ima/ima_main.c:633 security_file_post_open+0xbb/0x290 security/security.c:3199 do_open fs/namei.c:3977 [inline] path_openat+0x2f32/0x3840 fs/namei.c:4134 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (btrfs_trans_num_writers){++++}-{0:0}: reacquire_held_locks+0x127/0x1d0 kernel/locking/lockdep.c:5385 __lock_release kernel/locking/lockdep.c:5574 [inline] lock_release+0x1b4/0x3e0 kernel/locking/lockdep.c:5889 percpu_up_read include/linux/percpu-rwsem.h:112 [inline] __sb_end_write include/linux/fs.h:1911 [inline] sb_end_intwrite+0x26/0x1c0 include/linux/fs.h:2028 __btrfs_end_transaction+0x248/0x640 fs/btrfs/transaction.c:1076 btrfs_finish_one_ordered+0x139a/0x21a0 fs/btrfs/inode.c:3236 btrfs_work_helper+0x39b/0xc00 fs/btrfs/async-thread.c:312 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #1 (btrfs_ordered_extent){++++}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 btrfs_start_ordered_extent_nowriteback+0x39c/0x6e0 fs/btrfs/ordered-data.c:896 lock_extents_for_read+0x151/0xb50 fs/btrfs/extent_io.c:1314 btrfs_readahead+0x183/0x730 fs/btrfs/extent_io.c:2686 read_pages+0x17a/0x580 mm/readahead.c:163 page_cache_ra_unbounded+0x699/0x8e0 mm/readahead.c:302 page_cache_sync_readahead include/linux/pagemap.h:1379 [inline] defrag_one_cluster fs/btrfs/defrag.c:1313 [inline] btrfs_defrag_file+0xa02/0x2eb0 fs/btrfs/defrag.c:1455 btrfs_ioctl_defrag+0x389/0x490 fs/btrfs/ioctl.c:2572 btrfs_ioctl+0xbe2/0xd00 fs/btrfs/ioctl.c:-1 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (mapping.invalidate_lock#3){.+.+}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_read+0x97/0x1f0 kernel/locking/rwsem.c:1537 filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] page_cache_ra_unbounded+0x1a3/0x8e0 mm/readahead.c:233 do_sync_mmap_readahead+0x554/0x670 mm/filemap.c:3340 filemap_fault+0x6c2/0x12c0 mm/filemap.c:3489 __do_fault+0x138/0x390 mm/memory.c:5280 do_shared_fault mm/memory.c:5762 [inline] do_fault mm/memory.c:5836 [inline] do_pte_missing mm/memory.c:4361 [inline] handle_pte_fault mm/memory.c:6177 [inline] __handle_mm_fault mm/memory.c:6318 [inline] handle_mm_fault+0x117f/0x3400 mm/memory.c:6487 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 filldir+0x2b6/0x6c0 fs/readdir.c:295 dir_emit include/linux/fs.h:3986 [inline] kernfs_fop_readdir+0x53a/0x870 fs/kernfs/dir.c:1910 iterate_dir+0x3a5/0x580 fs/readdir.c:108 __do_sys_getdents fs/readdir.c:326 [inline] __se_sys_getdents+0xe4/0x250 fs/readdir.c:312 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: mapping.invalidate_lock#3 --> &fs_info->qgroup_ioctl_lock --> &root->kernfs_rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&root->kernfs_rwsem); lock(&fs_info->qgroup_ioctl_lock); lock(&root->kernfs_rwsem); rlock(mapping.invalidate_lock#3); *** DEADLOCK *** 3 locks held by syz.7.719/14515: #0: ffff888050799528 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1232 #1: ffff88806622d3f8 (&type->i_mutex_dir_key#4){++++}-{4:4}, at: iterate_dir+0x29e/0x580 fs/readdir.c:101 #2: ffff88813ff74238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_fop_readdir+0x267/0x870 fs/kernfs/dir.c:1893 stack backtrace: CPU: 1 UID: 0 PID: 14515 Comm: syz.7.719 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 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+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_read+0x97/0x1f0 kernel/locking/rwsem.c:1537 filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] page_cache_ra_unbounded+0x1a3/0x8e0 mm/readahead.c:233 do_sync_mmap_readahead+0x554/0x670 mm/filemap.c:3340 filemap_fault+0x6c2/0x12c0 mm/filemap.c:3489 __do_fault+0x138/0x390 mm/memory.c:5280 do_shared_fault mm/memory.c:5762 [inline] do_fault mm/memory.c:5836 [inline] do_pte_missing mm/memory.c:4361 [inline] handle_pte_fault mm/memory.c:6177 [inline] __handle_mm_fault mm/memory.c:6318 [inline] handle_mm_fault+0x117f/0x3400 mm/memory.c:6487 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:filldir+0x2b6/0x6c0 fs/readdir.c:296 Code: 87 73 02 00 00 0f 01 cb 0f ae e8 48 8b 44 24 50 49 89 44 24 08 48 8b 4c 24 08 48 8b 44 24 58 48 89 01 48 8b 04 24 8b 54 24 1c <66> 89 41 10 80 e2 0f 41 89 c7 42 88 54 39 ff 49 63 ee c6 44 29 12 RSP: 0018:ffffc9001aed7c58 EFLAGS: 00050283 RAX: 0000000000000020 RBX: ffffc9001aed7e38 RCX: 0000200000001ff0 RDX: 0000000000000004 RSI: 0000200000001fd8 RDI: 0000200000002010 RBP: 00007ffffffff000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed100a568001 R12: 0000200000001fd8 R13: ffffffff8aea35e0 R14: 0000000000000006 R15: 0000200000002010 dir_emit include/linux/fs.h:3986 [inline] kernfs_fop_readdir+0x53a/0x870 fs/kernfs/dir.c:1910 iterate_dir+0x3a5/0x580 fs/readdir.c:108 __do_sys_getdents fs/readdir.c:326 [inline] __se_sys_getdents+0xe4/0x250 fs/readdir.c:312 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f45faaaefc9 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:00007f45f08cc038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007f45fad06180 RCX: 00007f45faaaefc9 RDX: 0000000000000117 RSI: 0000200000001fc0 RDI: 000000000000000c RBP: 00007f45fab31f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f45fad06218 R14: 00007f45fad06180 R15: 00007ffe1c9c7da8 ---------------- Code disassembly (best guess): 0: 87 73 02 xchg %esi,0x2(%rbx) 3: 00 00 add %al,(%rax) 5: 0f 01 cb stac 8: 0f ae e8 lfence b: 48 8b 44 24 50 mov 0x50(%rsp),%rax 10: 49 89 44 24 08 mov %rax,0x8(%r12) 15: 48 8b 4c 24 08 mov 0x8(%rsp),%rcx 1a: 48 8b 44 24 58 mov 0x58(%rsp),%rax 1f: 48 89 01 mov %rax,(%rcx) 22: 48 8b 04 24 mov (%rsp),%rax 26: 8b 54 24 1c mov 0x1c(%rsp),%edx * 2a: 66 89 41 10 mov %ax,0x10(%rcx) <-- trapping instruction 2e: 80 e2 0f and $0xf,%dl 31: 41 89 c7 mov %eax,%r15d 34: 42 88 54 39 ff mov %dl,-0x1(%rcx,%r15,1) 39: 49 63 ee movslq %r14d,%rbp 3c: c6 .byte 0xc6 3d: 44 29 12 sub %r10d,(%rdx) --- 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