Message-ID: <67491c3c.050a0220.253251.009d.GAE@google.com>
Date: Thu, 28 Nov 2024 17:43:24 -0800
From: syzbot <syzbot+8df514c431bd240c5644@...kaller.appspotmail.com>
To: almaz.alexandrovich@...agon-software.com, linux-kernel@...r.kernel.org, 
	ntfs3@...ts.linux.dev, syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [ntfs3?] possible deadlock in mark_as_free_ex (2)

syzbot has found a reproducer for the following issue on:

HEAD commit:    7af08b57bcb9 Merge tag 'trace-v6.13-2' of git://git.kernel..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1607cf78580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=129a9798def93175
dashboard link: https://syzkaller.appspot.com/bug?extid=8df514c431bd240c5644
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=136b33c0580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f6e67f04bc76/disk-7af08b57.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/31932bddea1f/vmlinux-7af08b57.xz
kernel image: https://storage.googleapis.com/syzbot-assets/62707034e0dd/bzImage-7af08b57.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/8dd5f7e91d9f/mount_0.gz
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/732aad914e95/mount_3.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8df514c431bd240c5644@...kaller.appspotmail.com

loop2: detected capacity change from 0 to 4096
======================================================
WARNING: possible circular locking dependency detected
6.12.0-syzkaller-10689-g7af08b57bcb9 #0 Not tainted
------------------------------------------------------
syz.2.134/6316 is trying to acquire lock:
ffff88807b844270 (&wnd->rw_lock){++++}-{4:4}, at: mark_as_free_ex+0x3e/0x390 fs/ntfs3/fsntfs.c:2484

but task is already holding lock:
ffff88805ac3adc0 (&ni->file.run_lock#2){++++}-{4:4}, at: ntfs_truncate fs/ntfs3/file.c:505 [inline]
ffff88805ac3adc0 (&ni->file.run_lock#2){++++}-{4:4}, at: ntfs_setattr+0x6d3/0xb80 fs/ntfs3/file.c:824

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->file.run_lock#2){++++}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
       run_unpack_ex+0x55e/0x9e0 fs/ntfs3/run.c:1119
       ntfs_read_mft fs/ntfs3/inode.c:401 [inline]
       ntfs_iget5+0x1f9a/0x37b0 fs/ntfs3/inode.c:537
       dir_search_u+0x2fe/0x3a0 fs/ntfs3/dir.c:264
       ntfs_lookup+0x106/0x1f0 fs/ntfs3/namei.c:85
       lookup_one_qstr_excl+0x11f/0x260 fs/namei.c:1692
       do_renameat2+0x670/0x13f0 fs/namei.c:5165
       __do_sys_rename fs/namei.c:5271 [inline]
       __se_sys_rename fs/namei.c:5269 [inline]
       __x64_sys_rename+0x82/0x90 fs/namei.c:5269
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&wnd->rw_lock){++++}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693
       mark_as_free_ex+0x3e/0x390 fs/ntfs3/fsntfs.c:2484
       run_deallocate_ex+0x244/0x5f0 fs/ntfs3/attrib.c:122
       attr_set_size+0x168d/0x4300 fs/ntfs3/attrib.c:753
       ntfs_truncate fs/ntfs3/file.c:506 [inline]
       ntfs_setattr+0x7a4/0xb80 fs/ntfs3/file.c:824
       notify_change+0xbca/0xe90 fs/attr.c:552
       do_truncate+0x220/0x310 fs/open.c:65
       handle_truncate fs/namei.c:3449 [inline]
       do_open fs/namei.c:3832 [inline]
       path_openat+0x2e1e/0x3590 fs/namei.c:3987
       do_filp_open+0x27f/0x4e0 fs/namei.c:4014
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1402
       do_sys_open fs/open.c:1417 [inline]
       __do_sys_creat fs/open.c:1495 [inline]
       __se_sys_creat fs/open.c:1489 [inline]
       __x64_sys_creat+0x123/0x170 fs/open.c:1489
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ni->file.run_lock#2);
                               lock(&wnd->rw_lock);
                               lock(&ni->file.run_lock#2);
  lock(&wnd->rw_lock);

 *** DEADLOCK ***

4 locks held by syz.2.134/6316:
 #0: ffff88807b842420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515
 #1: ffff88805ac3afa8 (&sb->s_type->i_mutex_key#22){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
 #1: ffff88805ac3afa8 (&sb->s_type->i_mutex_key#22){+.+.}-{4:4}, at: do_truncate+0x20c/0x310 fs/open.c:63
 #2: ffff88805ac3ad10 (&ni->ni_lock#3/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1110 [inline]
 #2: ffff88805ac3ad10 (&ni->ni_lock#3/5){+.+.}-{4:4}, at: ntfs_truncate fs/ntfs3/file.c:503 [inline]
 #2: ffff88805ac3ad10 (&ni->ni_lock#3/5){+.+.}-{4:4}, at: ntfs_setattr+0x6bf/0xb80 fs/ntfs3/file.c:824
 #3: ffff88805ac3adc0 (&ni->file.run_lock#2){++++}-{4:4}, at: ntfs_truncate fs/ntfs3/file.c:505 [inline]
 #3: ffff88805ac3adc0 (&ni->file.run_lock#2){++++}-{4:4}, at: ntfs_setattr+0x6d3/0xb80 fs/ntfs3/file.c:824

stack backtrace:
CPU: 1 UID: 0 PID: 6316 Comm: syz.2.134 Not tainted 6.12.0-syzkaller-10689-g7af08b57bcb9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693
 mark_as_free_ex+0x3e/0x390 fs/ntfs3/fsntfs.c:2484
 run_deallocate_ex+0x244/0x5f0 fs/ntfs3/attrib.c:122
 attr_set_size+0x168d/0x4300 fs/ntfs3/attrib.c:753
 ntfs_truncate fs/ntfs3/file.c:506 [inline]
 ntfs_setattr+0x7a4/0xb80 fs/ntfs3/file.c:824
 notify_change+0xbca/0xe90 fs/attr.c:552
 do_truncate+0x220/0x310 fs/open.c:65
 handle_truncate fs/namei.c:3449 [inline]
 do_open fs/namei.c:3832 [inline]
 path_openat+0x2e1e/0x3590 fs/namei.c:3987
 do_filp_open+0x27f/0x4e0 fs/namei.c:4014
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402
 do_sys_open fs/open.c:1417 [inline]
 __do_sys_creat fs/open.c:1495 [inline]
 __se_sys_creat fs/open.c:1489 [inline]
 __x64_sys_creat+0x123/0x170 fs/open.c:1489
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb9f1980809
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:00007fb9f282a058 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007fb9f1b45fa0 RCX: 00007fb9f1980809
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200002c0
RBP: 00007fb9f19f393e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb9f1b45fa0 R15: 00007ffcedbec7c8
 </TASK>


---
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.

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