From: syzbot <syzbot+8bd419f88e25ab12cb75@syzkaller.appspotmail.com>
To: akpm@linux-foundation.org,
almaz.alexandrovich@paragon-software.com, jack@suse.cz,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, ntfs3@lists.linux.dev,
syzkaller-bugs@googlegroups.com, willy@infradead.org
Subject: Re: [syzbot] [ntfs3?] possible deadlock in page_cache_ra_order
Date: Mon, 14 Sep 2026 12:17:36 -0700 [thread overview]
Message-ID: <6aa84850.f81106d8.2ab401.0053.GAE@google.com> (raw)
In-Reply-To: <6a1b9770.fd5edf16.2e7427.0008.GAE@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: 704340f1cd0d Merge tag 'x86_urgent_for_7.3-rc4' of git://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14118df9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b454dc6b1b7acd30
dashboard link: https://syzkaller.appspot.com/bug?extid=8bd419f88e25ab12cb75
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=154788c9580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=134788c9580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a1f812f889ad/disk-704340f1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8aa4ccae83ac/vmlinux-704340f1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8f86a50bf181/bzImage-704340f1.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/54fd657ced87/mount_0.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8bd419f88e25ab12cb75@syzkaller.appspotmail.com
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)
---
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.
prev parent reply other threads:[~2026-09-14 19:17 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-31 2:05 [syzbot] [mm?] [fs?] " syzbot
2026-09-14 19:17 ` syzbot [this message]
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