[syzbot] [ntfs3?] possible deadlock in ntfs_set_size (3)

From: syzbot
Date: Wed Oct 09 2024 - 15:06:35 EST

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Hello,

syzbot found the following issue on:

HEAD commit: 8f602276d390 Merge tag 'bcachefs-2024-10-05' of git://evil..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10520327980000
kernel config: https://syzkaller.appspot.com/x/.config?x=9775e9a1af839423
dashboard link: https://syzkaller.appspot.com/bug?extid=bc7ded2e21137a228c72
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c85b02a6dfd7/disk-8f602276.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e428dbf555c6/vmlinux-8f602276.xz
kernel image: https://storage.googleapis.com/syzbot-assets/24dbed728796/bzImage-8f602276.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bc7ded2e21137a228c72@xxxxxxxxxxxxxxxxxxxxxxxxx

======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc1-syzkaller-00349-g8f602276d390 #0 Not tainted
------------------------------------------------------
syz.0.245/7337 is trying to acquire lock:
ffff88805e861e60 (&ni->ni_lock/4){+.+.}-{3:3}, at: ni_lock fs/ntfs3/ntfs_fs.h:1109 [inline]
ffff88805e861e60 (&ni->ni_lock/4){+.+.}-{3:3}, at: ntfs_set_size+0x12e/0x200 fs/ntfs3/inode.c:846

but task is already holding lock:
ffff88805e8620f8 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: inode_trylock include/linux/fs.h:835 [inline]
ffff88805e8620f8 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: ntfs_file_write_iter+0x247/0x740 fs/ntfs3/file.c:1165

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
down_write+0x99/0x220 kernel/locking/rwsem.c:1577
inode_lock include/linux/fs.h:815 [inline]
ntfs_file_mmap+0x5bc/0x850 fs/ntfs3/file.c:367
call_mmap include/linux/fs.h:2172 [inline]
mmap_region+0x1add/0x2990 mm/mmap.c:1440
do_mmap+0x8f0/0x1000 mm/mmap.c:496
vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588
ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:542
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

-> #1 (&mm->mmap_lock){++++}-{3:3}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
__might_fault+0xc6/0x120 mm/memory.c:6700
_inline_copy_to_user include/linux/uaccess.h:183 [inline]
_copy_to_user+0x2a/0xb0 lib/usercopy.c:26
copy_to_user include/linux/uaccess.h:216 [inline]
fiemap_fill_next_extent+0x235/0x410 fs/ioctl.c:145
ni_fiemap+0x4f5/0x1910 fs/ntfs3/frecord.c:1993
ntfs_fiemap+0x132/0x180 fs/ntfs3/file.c:1278
ioctl_fiemap fs/ioctl.c:220 [inline]
do_vfs_ioctl+0x1bf8/0x2e40 fs/ioctl.c:841
__do_sys_ioctl fs/ioctl.c:905 [inline]
__se_sys_ioctl+0x81/0x170 fs/ioctl.c:893
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 (&ni->ni_lock/4){+.+.}-{3:3}:
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+0x1384/0x2050 kernel/locking/lockdep.c:5202
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
ni_lock fs/ntfs3/ntfs_fs.h:1109 [inline]
ntfs_set_size+0x12e/0x200 fs/ntfs3/inode.c:846
ntfs_extend+0x163/0x480 fs/ntfs3/file.c:397
ntfs_file_write_iter+0x3ce/0x740 fs/ntfs3/file.c:1187
new_sync_write fs/read_write.c:590 [inline]
vfs_write+0xa6d/0xc90 fs/read_write.c:683
ksys_write+0x183/0x2b0 fs/read_write.c:736
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:

Chain exists of:
&ni->ni_lock/4 --> &mm->mmap_lock --> &sb->s_type->i_mutex_key#23

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&sb->s_type->i_mutex_key#23);
lock(&mm->mmap_lock);
lock(&sb->s_type->i_mutex_key#23);
lock(&ni->ni_lock/4);

*** DEADLOCK ***

3 locks held by syz.0.245/7337:
#0: ffff8880260022b8 (&f->f_pos_lock){+.+.}-{3:3}, at: fdget_pos+0x24e/0x320 fs/file.c:1160
#1: ffff8880126be420 (sb_writers#15){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
#1: ffff8880126be420 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679
#2: ffff88805e8620f8 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: inode_trylock include/linux/fs.h:835 [inline]
#2: ffff88805e8620f8 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: ntfs_file_write_iter+0x247/0x740 fs/ntfs3/file.c:1165

stack backtrace:
CPU: 1 UID: 0 PID: 7337 Comm: syz.0.245 Not tainted 6.12.0-rc1-syzkaller-00349-g8f602276d390 #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+0x1384/0x2050 kernel/locking/lockdep.c:5202
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
ni_lock fs/ntfs3/ntfs_fs.h:1109 [inline]
ntfs_set_size+0x12e/0x200 fs/ntfs3/inode.c:846
ntfs_extend+0x163/0x480 fs/ntfs3/file.c:397
ntfs_file_write_iter+0x3ce/0x740 fs/ntfs3/file.c:1187
new_sync_write fs/read_write.c:590 [inline]
vfs_write+0xa6d/0xc90 fs/read_write.c:683
ksys_write+0x183/0x2b0 fs/read_write.c:736
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: 0033:0x7fdd5297dff9
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:00007fdd5381b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fdd52b35f80 RCX: 00007fdd5297dff9
RDX: 0000000000001006 RSI: 0000000020006640 RDI: 0000000000000006
RBP: 00007fdd529f0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdd52b35f80 R15: 00007ffdd949f3f8
</TASK>

---
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