possible deadlock in page_cache_ra_order

Status: upstream: reported C repro on 2026/05/31 02:05
Subsystems: ntfs3
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+8bd419f88e25ab12cb75@syzkaller.appspotmail.com
First crash: 125d, last: 14d
Cause bisection: introduced by (bisect log) :
commit d62cf685d12e95cc0a4122c43cd9f0eb8bba0b4c
Author: ZhengYuan Huang <gality369@gmail.com>
Date: Mon Apr 27 07:26:50 2026 +0000

  fs/ntfs3: hold ni_lock across readdir metadata walk

Crash: possible deadlock in page_cache_ra_order (log)
Repro: C syz .config
  
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ID Workflow Result Correct Bug Created Started Finished Revision
6842e9d3 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ possible deadlock in page_cache_ra_order 2026/05/29 22:51 2026/05/29 22:51 2026/05/29 23:47 6b4a8443
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [mm?] [fs?] possible deadlock in page_cache_ra_order 0 (3) 2026/09/16 22:40
[syzbot] Monthly fs report (Jul 2026) 0 (1) 2026/07/10 20:32

Sample crash report:
ntfs3(loop1): ino=1f, mi_enum_attr
ntfs3(loop1): Mark volume as dirty due to NTFS errors
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.68/6182 is trying to acquire lock:
ffff88803364abd0 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1089 [inline]
ffff88803364abd0 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: do_page_cache_ra mm/readahead.c:347 [inline]
ffff88803364abd0 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: page_cache_ra_order+0x2b1/0x4a0 mm/readahead.c:558

but task is already holding lock:
ffff88803364aee0 (&ni->ni_lock/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1247 [inline]
ffff88803364aee0 (&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_iomap_begin+0x4f0/0xf30 fs/ntfs3/inode.c:978
       iomap_iter_next include/linux/iomap.h:382 [inline]
       ntfs_iomap_next+0x5b6/0x880 fs/ntfs3/inode.c:2319
       iomap_iter+0xe2/0xec0 fs/iomap/iter.c:122
       iomap_readahead+0xa4a/0xe80 fs/iomap/buffered-io.c:751
       ntfs_readahead+0x193/0x210 fs/ntfs3/inode.c:880
       read_pages+0x193/0x5a0 mm/readahead.c:174
       page_cache_ra_unbounded+0x679/0x8f0 mm/readahead.c:315
       do_page_cache_ra mm/readahead.c:348 [inline]
       page_cache_ra_order+0x2c1/0x4a0 mm/readahead.c:558
       filemap_get_pages+0x493/0x1e80 mm/filemap.c:2714
       filemap_read+0x429/0x11e0 mm/filemap.c:2824
       __kernel_read+0x4d3/0x970 fs/read_write.c:532
       integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28
       ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline]
       ima_calc_file_hash+0x45d/0x8a0 security/integrity/ima/ima_crypto.c:280
       ima_collect_measurement+0x521/0xa10 security/integrity/ima/ima_api.c:300
       process_measurement+0x1282/0x1c20 security/integrity/ima/ima_main.c:425
       ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:685
       security_file_post_open+0xb3/0x260 security/security.c:2755
       do_open fs/namei.c:4839 [inline]
       path_openat+0x148a/0x1d60 fs/namei.c:5000
       do_file_open+0x23e/0x4a0 fs/namei.c:5029
       do_sys_openat2+0x115/0x200 fs/open.c:1417
       do_sys_open fs/open.c:1423 [inline]
       __do_sys_openat fs/open.c:1439 [inline]
       __se_sys_openat fs/open.c:1434 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1434
       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 (mapping.invalidate_lock#3){.+.+}-{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+0x97/0x200 kernel/locking/rwsem.c:1574
       filemap_invalidate_lock_shared include/linux/fs.h:1089 [inline]
       do_page_cache_ra mm/readahead.c:347 [inline]
       page_cache_ra_order+0x2b1/0x4a0 mm/readahead.c:558
       do_sync_mmap_readahead+0x4d6/0x7c0 mm/filemap.c:3443
       filemap_fault+0x7e2/0x13c0 mm/filemap.c:3597
       __do_fault+0x138/0x2a0 mm/memory.c:5565
       do_shared_fault mm/memory.c:6064 [inline]
       do_fault mm/memory.c:6138 [inline]
       do_pte_missing+0x659/0x28f0 mm/memory.c:4700
       handle_pte_fault mm/memory.c:6558 [inline]
       __handle_mm_fault mm/memory.c:6707 [inline]
       handle_mm_fault+0xf64/0x28c0 mm/memory.c:6876
       do_user_addr_fault+0x746/0x1340 arch/x86/mm/fault.c:1394
       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:286
       dir_emit include/linux/fs.h:3607 [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+0x2f1/0x4e0 fs/readdir.c:110
       __do_sys_getdents fs/readdir.c:319 [inline]
       __se_sys_getdents+0xf1/0x270 fs/readdir.c:304
       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(mapping.invalidate_lock#3);
                               lock(&ni->ni_lock/5);
  rlock(mapping.invalidate_lock#3);

 *** DEADLOCK ***

locks held by syz.1.68/6182: 3, last CPU#0:
 #0: ffff88803c3c2328 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
 #1: ffff88803364b1a8 (&type->i_mutex_dir_key#8){++++}-{4:4}, at: iterate_dir+0x215/0x4e0 fs/readdir.c:103
 #2: ffff88803364aee0 (&ni->ni_lock/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1247 [inline]
 #2: ffff88803364aee0 (&ni->ni_lock/5){+.+.}-{4:4}, at: ntfs_readdir+0x717/0xf70 fs/ntfs3/dir.c:541

stack backtrace:
CPU: 0 UID: 0 PID: 6182 Comm: syz.1.68 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 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+0x97/0x200 kernel/locking/rwsem.c:1574
 filemap_invalidate_lock_shared include/linux/fs.h:1089 [inline]
 do_page_cache_ra mm/readahead.c:347 [inline]
 page_cache_ra_order+0x2b1/0x4a0 mm/readahead.c:558
 do_sync_mmap_readahead+0x4d6/0x7c0 mm/filemap.c:3443
 filemap_fault+0x7e2/0x13c0 mm/filemap.c:3597
 __do_fault+0x138/0x2a0 mm/memory.c:5565
 do_shared_fault mm/memory.c:6064 [inline]
 do_fault mm/memory.c:6138 [inline]
 do_pte_missing+0x659/0x28f0 mm/memory.c:4700
 handle_pte_fault mm/memory.c:6558 [inline]
 __handle_mm_fault mm/memory.c:6707 [inline]
 handle_mm_fault+0xf64/0x28c0 mm/memory.c:6876
 do_user_addr_fault+0x746/0x1340 arch/x86/mm/fault.c:1394
 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:288
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 e9 35 7f 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:ffffc90004cf7ab0 EFLAGS: 00050293
RAX: 00000000000009e8 RBX: 0000200000002050 RCX: ffff888026543e80
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000007
RBP: 0000000000000020 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1004ca87d1 R12: ffff88803ae8a000
R13: 0000000000000005 R14: 0000000000000005 R15: 0000200000002030
 dir_emit include/linux/fs.h:3607 [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+0x2f1/0x4e0 fs/readdir.c:110
 __do_sys_getdents fs/readdir.c:319 [inline]
 __se_sys_getdents+0xf1/0x270 fs/readdir.c:304
 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: 0033:0x7fe25947e159
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:00007fe258a9c028 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007fe259706180 RCX: 00007fe25947e159
RDX: 0000000020002078 RSI: 0000200000001fc0 RDI: 0000000000000007
RBP: 00007fe25951503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe259706218 R14: 00007fe259706180 R15: 00007ffeaad84d78
 </TASK>
ntfs3(loop1): ino=1f, mi_enum_attr
----------------
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 e9 35 7f ff       	call   0xff7f360b
  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)

Crashes (22):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/14 19:16 upstream 704340f1cd0d 81a27d1a .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/09/14 17:26 upstream 704340f1cd0d 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/09/14 17:20 upstream 704340f1cd0d 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/09/14 17:20 upstream 704340f1cd0d 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/09/14 17:19 upstream 704340f1cd0d 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/09/14 17:18 upstream 704340f1cd0d 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/09/14 17:17 upstream 704340f1cd0d 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/09/14 17:17 upstream 704340f1cd0d 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/09/14 17:16 upstream 704340f1cd0d 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/09/14 17:15 upstream 704340f1cd0d 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/09/14 17:11 upstream 704340f1cd0d 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/08/02 01:47 upstream 02dc699f83d0 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/07/18 08:46 upstream 94515f3a7d42 72524a66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/07/12 14:14 upstream 44696aa3a489 d78ea535 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/07/11 23:16 upstream dd3210c47e8d d78ea535 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in page_cache_ra_order
2026/07/04 06:46 upstream d2c9a99135da fcece630 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in page_cache_ra_order
2026/08/24 03:20 linux-next 903c1cf6dff9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in page_cache_ra_order
2026/05/27 07:58 linux-next e7e28506af98 2b01f00e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in page_cache_ra_order
2026/05/27 07:55 linux-next e7e28506af98 2b01f00e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in page_cache_ra_order
2026/05/27 07:54 linux-next e7e28506af98 2b01f00e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in page_cache_ra_order
2026/05/27 07:54 linux-next e7e28506af98 2b01f00e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in page_cache_ra_order
2026/05/27 01:58 linux-next e7e28506af98 2b01f00e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in page_cache_ra_order
* Struck through repros no longer work on HEAD.