From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f198.google.com (mail-oi1-f198.google.com [209.85.167.198]) (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 196434FDA75 for ; Tue, 13 Oct 2026 13:53:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791899620; cv=none; b=TZY0U4JJGRnLCwkIHgkmCfRPJGLNLGmE59igmUbj7P3JzRDUq1DaJn5ZvfW1Kk+GkYC3uPwylGLNHVa1WrQwpWvea3he/KTUo+358ysRpX71OPeynHNFk3NWPxQraUo/yIsy2BdaPEFVmKrzG+6sV08mqUQ20CG9Jy9NM+ippYU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791899620; c=relaxed/simple; bh=hZL72XOUPUJc5kL0hCiQyhutYCYGmYfDAEkJs6SJdJE=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=qRHR6pDq/HLokQ5UfuoEcm60b5lNT8XJabn1Qj7/yWe8uORdt9xBtkB47QzQjNdgk2khDareuy1+2weX4gBUH6Z104/cG7Ts628yQZSnUc50mzcQ4RVf0f1rmUdFOWMqhGWcmdmcEwi7NRKMsOPdSuovU4myMbqEhL8gsRo2IS4= 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=209.85.167.198 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-f198.google.com with SMTP id 5614622812f47-4ab260600easo6831459b6e.1 for ; Tue, 13 Oct 2026 06:53:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791899618; x=1792504418; 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=O82mp/mFFeRVeGwjdUjNn3HGa5rUeYT+1hm74Uda2hk=; b=ZanTIf2pTmM2+grZLxw/xkplPcdm9mZ2GTBcOKg6LwAD1pxHViI4h1VNitXPzIx3Ik eb8kP84scc5W4CZVfII7he3yvz/gCC4jm2TXDjVmEuLPeOK3oTzttbtoBf0cZOHq+OJG jbKGPEVc5sQ3nCy1yg+nMSYMRuf73UQIEbmA6zXvtwmD0hdBECJqdz0oDEkWHm2aLc4o lgwMb0DLRbtcSb5kWGRu5QGEtDXyat3SjOcGbK52LStCFFwQDhZdDbuY5EIosQSicyaI 4LmpBN4Q1/MJ+Wn0PU8VGQM+xavJgGhxYMSCbAME3EAFNcupb9nhEQNZAolxuSZ8Hc/1 w4UA== X-Forwarded-Encrypted: i=1; AKwUvBw6ibhmHccMhTAJWq5vfP+2qICCPa6h8X9+18Yt7T0vDgJN5R4wTnbDN7PQbOl6ULaUypFeXUCSjL0muj8=@vger.kernel.org X-Gm-Message-State: AFq9FYICbWTiEmUOXSyR046smTliJ+FgdyRyaq5aXmcyky2al/yXGcfV lbTApOUNdD+GdgnZKE2MyM7DUGJh1LOD7twC/g3l6xuz5rGCF4tSfnTet2BfQrzixPFiDb1LuCp 2P/r2UhnbtVubE1IrsKfMT8RYUad/+SJc/SwL+PBMWfUiw/FRg4q6MT+jx8A= 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:a554:10b0:521:561a:8e90 with SMTP id 5614622812f47-52156397ac3mr2670451b6e.3.1791899617952; Tue, 13 Oct 2026 06:53:37 -0700 (PDT) Date: Tue, 13 Oct 2026 06:53:37 -0700 In-Reply-To: <6a42cfca.9dc7bc9d.3393b4.0008.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6ace37e1.0e5b5d80.2c029c.06da.GAE@google.com> Subject: Re: [syzbot] [ntfs3?] possible deadlock in ntfs_readdir From: syzbot To: almaz.alexandrovich@paragon-software.com, gality369@gmail.com, linux-kernel@vger.kernel.org, ntfs3@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: 24a19b953e2a Linux 7.3-rc7 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=118a55c9580000 kernel config: https://syzkaller.appspot.com/x/.config?x=df4bbab1c2172b9f dashboard link: https://syzkaller.appspot.com/bug?extid=cfc6e8106bec1c524f7d compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1575d40d580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14f68dd1580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/71ab5ff0ed88/disk-24a19b95.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/f5849c6ea337/vmlinux-24a19b95.xz kernel image: https://storage.googleapis.com/syzbot-assets/cf747b187062/bzImage-24a19b95.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/dd39b95ec4ba/mount_0.gz The issue was bisected to: commit d62cf685d12e95cc0a4122c43cd9f0eb8bba0b4c Author: ZhengYuan Huang Date: Mon Apr 27 07:26:50 2026 +0000 fs/ntfs3: hold ni_lock across readdir metadata walk bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1376eb49580000 final oops: https://syzkaller.appspot.com/x/report.txt?x=10f6eb49580000 console output: https://syzkaller.appspot.com/x/log.txt?x=1776eb49580000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+cfc6e8106bec1c524f7d@syzkaller.appspotmail.com Fixes: d62cf685d12e ("fs/ntfs3: hold ni_lock across readdir metadata walk") ntfs3(loop1): failed to convert "c46c" to cp855 ntfs3(loop1): ino=20, mi_enum_attr ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.40/6092 is trying to acquire lock: ffff88803a8344b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:609 but task is already holding lock: ffff88805ecb73c8 (&ni->ni_lock/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1247 [inline] ffff88805ecb73c8 (&ni->ni_lock/5){+.+.}-{4:4}, at: ntfs_readdir+0x717/0xf70 fs/ntfs3/dir.c:541 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&ni->ni_lock/5){+.+.}-{4:4}: __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:580 ni_lock fs/ntfs3/ntfs_fs.h:1247 [inline] attr_data_get_block+0x1cd/0x2c0 fs/ntfs3/attrib.c:976 ntfs_file_mmap_prepare+0x5b3/0xa20 fs/ntfs3/file.c:430 vfs_mmap_prepare include/linux/fs.h:2071 [inline] call_mmap_prepare mm/vma.c:2799 [inline] __mmap_region mm/vma.c:2888 [inline] mmap_region+0xebb/0x25c0 mm/vma.c:2989 do_mmap+0xe0e/0x1310 mm/mmap.c:573 vm_mmap_pgoff+0x275/0x4e0 mm/util.c:581 ksys_mmap_pgoff+0x4a6/0x720 mm/mmap.c:619 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&mm->mmap_lock){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 down_read_killable+0xa4/0x220 kernel/locking/rwsem.c:1599 mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:609 get_mmap_lock_carefully mm/mmap_lock.c:450 [inline] lock_mm_and_find_vma+0x2d6/0x340 mm/mmap_lock.c:501 do_user_addr_fault+0x343/0x1340 arch/x86/mm/fault.c:1366 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 stac arch/x86/include/asm/smap.h:-1 [inline] filldir+0x29f/0x630 fs/readdir.c:291 dir_emit include/linux/fs.h:3610 [inline] ntfs_dir_emit fs/ntfs3/dir.c:388 [inline] ntfs_read_hdr+0x8a7/0xc10 fs/ntfs3/dir.c:429 ntfs_readdir+0x9ab/0xf70 fs/ntfs3/dir.c:589 iterate_dir+0x3ea/0x8a0 fs/readdir.c:114 __do_sys_getdents fs/readdir.c:324 [inline] __se_sys_getdents+0xf1/0x270 fs/readdir.c:309 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ni->ni_lock/5); lock(&mm->mmap_lock); lock(&ni->ni_lock/5); rlock(&mm->mmap_lock); *** DEADLOCK *** locks held by syz.1.40/6092: 3, last CPU#0: #0: ffff888037c3c328 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259 #1: ffff88805ecb7690 (&type->i_mutex_dir_key#8){++++}-{4:4}, at: iterate_dir+0x293/0x8a0 fs/readdir.c:106 #2: ffff88805ecb73c8 (&ni->ni_lock/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1247 [inline] #2: ffff88805ecb73c8 (&ni->ni_lock/5){+.+.}-{4:4}, at: ntfs_readdir+0x717/0xf70 fs/ntfs3/dir.c:541 stack backtrace: CPU: 0 UID: 0 PID: 6092 Comm: syz.1.40 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219 check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 down_read_killable+0xa4/0x220 kernel/locking/rwsem.c:1599 mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:609 get_mmap_lock_carefully mm/mmap_lock.c:450 [inline] lock_mm_and_find_vma+0x2d6/0x340 mm/mmap_lock.c:501 do_user_addr_fault+0x343/0x1340 arch/x86/mm/fault.c:1366 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0010:filldir+0x29f/0x630 fs/readdir.c:293 Code: df 49 29 ef 48 b8 00 f0 ff ff ff 7f 00 00 49 39 c7 4c 0f 47 f8 bf 07 00 00 00 44 89 f6 e8 09 5b 7e ff 0f 01 cb 48 8b 44 24 20 <49> 89 47 08 48 bd 00 00 00 00 00 fc ff df 48 8b 44 24 40 48 89 03 RSP: 0018:ffffc90004f1fab0 EFLAGS: 00050293 RAX: 00000000000015a0 RBX: 0000200000008578 RCX: ffff888032ec1f40 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000007 RBP: 0000000000000020 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed10065d83e9 R12: ffff88803c9f4000 R13: 0000000000000005 R14: 0000000000000005 R15: 0000200000008558 dir_emit include/linux/fs.h:3610 [inline] ntfs_dir_emit fs/ntfs3/dir.c:388 [inline] ntfs_read_hdr+0x8a7/0xc10 fs/ntfs3/dir.c:429 ntfs_readdir+0x9ab/0xf70 fs/ntfs3/dir.c:589 iterate_dir+0x3ea/0x8a0 fs/readdir.c:114 __do_sys_getdents fs/readdir.c:324 [inline] __se_sys_getdents+0xf1/0x270 fs/readdir.c:309 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f210f74e2d9 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:00007f210edae028 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007f210f9d5fa0 RCX: 00007f210f74e2d9 RDX: 00000000000000b8 RSI: 0000200000008500 RDI: 0000000000000005 RBP: 00007f210f7e5888 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f210f9d6038 R14: 00007f210f9d5fa0 R15: 00007fff702375e8 ---------------- Code disassembly (best guess): 0: df 49 29 fisttps 0x29(%rcx) 3: ef out %eax,(%dx) 4: 48 b8 00 f0 ff ff ff movabs $0x7ffffffff000,%rax b: 7f 00 00 e: 49 39 c7 cmp %rax,%r15 11: 4c 0f 47 f8 cmova %rax,%r15 15: bf 07 00 00 00 mov $0x7,%edi 1a: 44 89 f6 mov %r14d,%esi 1d: e8 09 5b 7e ff call 0xff7e5b2b 22: 0f 01 cb stac 25: 48 8b 44 24 20 mov 0x20(%rsp),%rax * 2a: 49 89 47 08 mov %rax,0x8(%r15) <-- trapping instruction 2e: 48 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%rbp 35: fc ff df 38: 48 8b 44 24 40 mov 0x40(%rsp),%rax 3d: 48 89 03 mov %rax,(%rbx) --- 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.