[v6.1] possible deadlock in ntfs_read_folio

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 6449a0ba6843 Linux 6.1.19
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1150e7b2c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=9ed8b3ec03e8c126
dashboard link: https://syzkaller.appspot.com/bug?extid=784ba1c5dff60f10674b
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0ad616da3180/disk-6449a0ba.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/42677a30acb3/vmlinux-6449a0ba.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2e21fe35d03d/bzImage-6449a0ba.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+784ba1...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.1.19-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.1/8281 is trying to acquire lock:
ffff8880706c0940 (&rl->lock){++++}-{3:3}, at: ntfs_read_block fs/ntfs/aops.c:248 [inline]
ffff8880706c0940 (&rl->lock){++++}-{3:3}, at: ntfs_read_folio+0x14c9/0x29d0 fs/ntfs/aops.c:436

but task is already holding lock:
ffff8880706c3310 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x48/0x630 fs/ntfs/mft.c:154

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->mrec_lock){+.+.}-{3:3}:
lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
__mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
map_mft_record+0x48/0x630 fs/ntfs/mft.c:154
ntfs_map_runlist_nolock+0x4b4/0x1790 fs/ntfs/attrib.c:91
ntfs_prepare_pages_for_non_resident_write fs/ntfs/file.c:882 [inline]
ntfs_perform_write+0x2273/0x7510 fs/ntfs/file.c:1844
ntfs_file_write_iter+0x10e9/0x19f0 fs/ntfs/file.c:1917
call_write_iter include/linux/fs.h:2205 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x7ae/0xba0 fs/read_write.c:584
ksys_write+0x19c/0x2c0 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&rl->lock){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
down_read+0x39/0x50 kernel/locking/rwsem.c:1520
ntfs_read_block fs/ntfs/aops.c:248 [inline]
ntfs_read_folio+0x14c9/0x29d0 fs/ntfs/aops.c:436
filemap_read_folio+0x199/0x780 mm/filemap.c:2407
do_read_cache_folio+0x2ee/0x810 mm/filemap.c:3535
do_read_cache_page+0x32/0x220 mm/filemap.c:3577
read_mapping_page include/linux/pagemap.h:756 [inline]
ntfs_map_page fs/ntfs/aops.h:75 [inline]
ntfs_sync_mft_mirror+0x25b/0x1ad0 fs/ntfs/mft.c:480
write_mft_record_nolock+0x13f6/0x18d0 fs/ntfs/mft.c:805
write_mft_record+0x149/0x310 fs/ntfs/mft.h:95
__ntfs_write_inode+0x6ff/0xbb0 fs/ntfs/inode.c:3050
ntfs_commit_inode fs/ntfs/inode.h:300 [inline]
ntfs_put_super+0x676/0xf80 fs/ntfs/super.c:2307
generic_shutdown_super+0x130/0x340 fs/super.c:492
kill_block_super+0x7a/0xe0 fs/super.c:1441
deactivate_locked_super+0xa0/0x110 fs/super.c:332
cleanup_mnt+0x490/0x520 fs/namespace.c:1186
task_work_run+0x246/0x300 kernel/task_work.c:179
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0x6fb/0x2300 kernel/exit.c:869
do_group_exit+0x202/0x2b0 kernel/exit.c:1019
get_signal+0x16f7/0x17d0 kernel/signal.c:2858
arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:869
exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:203
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x60/0x2d0 kernel/entry/common.c:296
ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:299

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&ni->mrec_lock);
lock(&rl->lock);
lock(&ni->mrec_lock);
lock(&rl->lock);

*** DEADLOCK ***

2 locks held by syz-executor.1/8281:
#0: ffff88804016c0e0 (&type->s_umount_key#94){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
#1: ffff8880706c3310 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x48/0x630 fs/ntfs/mft.c:154

stack backtrace:
CPU: 1 PID: 8281 Comm: syz-executor.1 Not tainted 6.1.19-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2178
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
down_read+0x39/0x50 kernel/locking/rwsem.c:1520
ntfs_read_block fs/ntfs/aops.c:248 [inline]
ntfs_read_folio+0x14c9/0x29d0 fs/ntfs/aops.c:436
filemap_read_folio+0x199/0x780 mm/filemap.c:2407
do_read_cache_folio+0x2ee/0x810 mm/filemap.c:3535
do_read_cache_page+0x32/0x220 mm/filemap.c:3577
read_mapping_page include/linux/pagemap.h:756 [inline]
ntfs_map_page fs/ntfs/aops.h:75 [inline]
ntfs_sync_mft_mirror+0x25b/0x1ad0 fs/ntfs/mft.c:480
write_mft_record_nolock+0x13f6/0x18d0 fs/ntfs/mft.c:805
write_mft_record+0x149/0x310 fs/ntfs/mft.h:95
__ntfs_write_inode+0x6ff/0xbb0 fs/ntfs/inode.c:3050
ntfs_commit_inode fs/ntfs/inode.h:300 [inline]
ntfs_put_super+0x676/0xf80 fs/ntfs/super.c:2307
generic_shutdown_super+0x130/0x340 fs/super.c:492
kill_block_super+0x7a/0xe0 fs/super.c:1441
deactivate_locked_super+0xa0/0x110 fs/super.c:332
cleanup_mnt+0x490/0x520 fs/namespace.c:1186
task_work_run+0x246/0x300 kernel/task_work.c:179
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0x6fb/0x2300 kernel/exit.c:869
do_group_exit+0x202/0x2b0 kernel/exit.c:1019
get_signal+0x16f7/0x17d0 kernel/signal.c:2858
arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:869
exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:203
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x60/0x2d0 kernel/entry/common.c:296
ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:299
RIP: 0033:0x7f503ce8c0f9
Code: Unable to access opcode bytes at 0x7f503ce8c0cf.
RSP: 002b:00007f503db6d118 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: 0000000000000000 RBX: 00007f503cfabf80 RCX: 00007f503ce8c0f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f503cee7b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe992934ef R14: 00007f503db6d300 R15: 0000000000022000
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: e3a87a10f259 Linux 6.1.21
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12fadf26c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=390800ef8aeebc47

dashboard link: https://syzkaller.appspot.com/bug?extid=784ba1c5dff60f10674b
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=106e5f96c80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13ebaa41c80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9f5022ccd560/disk-e3a87a10.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f8524664c631/vmlinux-e3a87a10.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ad699b30c2c4/Image-e3a87a10.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/7d4bf9ecc45b/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+784ba1...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected

6.1.21-syzkaller #0 Not tainted
------------------------------------------------------
kworker/u4:0/4331 is trying to acquire lock:
ffff0000b186bac0 (&rl->lock){++++}-{3:3}, at: ntfs_read_block fs/ntfs/aops.c:248 [inline]
ffff0000b186bac0 (&rl->lock){++++}-{3:3}, at: ntfs_read_folio+0xf40/0x1d70 fs/ntfs/aops.c:436

but task is already holding lock:

ffff00003ff7e490 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x64/0x7b4 fs/ntfs/mft.c:154

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->mrec_lock){+.+.}-{3:3}:

__mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
map_mft_record+0x64/0x7b4 fs/ntfs/mft.c:154
ntfs_attr_extend_allocation+0x458/0x3470 fs/ntfs/attrib.c:2002
ntfs_prepare_file_for_write fs/ntfs/file.c:391 [inline]
ntfs_file_write_iter+0x2c8/0x17b0 fs/ntfs/file.c:1915

call_write_iter include/linux/fs.h:2205 [inline]
new_sync_write fs/read_write.c:491 [inline]

vfs_write+0x610/0x914 fs/read_write.c:584
ksys_write+0x15c/0x26c fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:646
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #0 (&rl->lock){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]

validate_chain kernel/locking/lockdep.c:3832 [inline]
__lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056
lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5669
down_read+0x5c/0x78 kernel/locking/rwsem.c:1520
ntfs_read_block fs/ntfs/aops.c:248 [inline]
ntfs_read_folio+0xf40/0x1d70 fs/ntfs/aops.c:436
filemap_read_folio+0x14c/0x39c mm/filemap.c:2407
do_read_cache_folio+0x24c/0x544 mm/filemap.c:3535
do_read_cache_page mm/filemap.c:3577 [inline]
read_cache_page+0x6c/0x180 mm/filemap.c:3586

read_mapping_page include/linux/pagemap.h:756 [inline]
ntfs_map_page fs/ntfs/aops.h:75 [inline]

ntfs_sync_mft_mirror+0x1cc/0x1890 fs/ntfs/mft.c:480
write_mft_record_nolock+0x100c/0x1630 fs/ntfs/mft.c:787
write_mft_record+0x144/0x1bc fs/ntfs/mft.h:95
__ntfs_write_inode+0x5cc/0xa78 fs/ntfs/inode.c:3050
ntfs_write_inode+0x68/0x90 fs/ntfs/super.c:2656
write_inode fs/fs-writeback.c:1440 [inline]
__writeback_single_inode+0x614/0x1770 fs/fs-writeback.c:1652
writeback_sb_inodes+0x978/0x16c0 fs/fs-writeback.c:1878
wb_writeback+0x414/0x1130 fs/fs-writeback.c:2052
wb_do_writeback fs/fs-writeback.c:2195 [inline]
wb_workfn+0x3a8/0x1034 fs/fs-writeback.c:2235
process_one_work+0x7ac/0x1404 kernel/workqueue.c:2289
worker_thread+0x8e4/0xfec kernel/workqueue.c:2436
kthread+0x24c/0x2d4 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&ni->mrec_lock);
lock(&rl->lock);
lock(&ni->mrec_lock);
lock(&rl->lock);

*** DEADLOCK ***

3 locks held by kworker/u4:0/4331:
#0: ffff0000c0e3d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2262
#1: ffff80001dca7c20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2264
#2: ffff00003ff7e490 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x64/0x7b4 fs/ntfs/mft.c:154

stack backtrace:
CPU: 0 PID: 4331 Comm: kworker/u4:0 Not tainted 6.1.21-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023

Workqueue: writeback wb_workfn (flush-7:0)
Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
dump_stack+0x1c/0x5c lib/dump_stack.c:113
print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2056
check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2178

check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]

validate_chain kernel/locking/lockdep.c:3832 [inline]
__lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056
lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5669
down_read+0x5c/0x78 kernel/locking/rwsem.c:1520
ntfs_read_block fs/ntfs/aops.c:248 [inline]
ntfs_read_folio+0xf40/0x1d70 fs/ntfs/aops.c:436
filemap_read_folio+0x14c/0x39c mm/filemap.c:2407
do_read_cache_folio+0x24c/0x544 mm/filemap.c:3535
do_read_cache_page mm/filemap.c:3577 [inline]
read_cache_page+0x6c/0x180 mm/filemap.c:3586

read_mapping_page include/linux/pagemap.h:756 [inline]
ntfs_map_page fs/ntfs/aops.h:75 [inline]

ntfs_sync_mft_mirror+0x1cc/0x1890 fs/ntfs/mft.c:480
write_mft_record_nolock+0x100c/0x1630 fs/ntfs/mft.c:787
write_mft_record+0x144/0x1bc fs/ntfs/mft.h:95
__ntfs_write_inode+0x5cc/0xa78 fs/ntfs/inode.c:3050
ntfs_write_inode+0x68/0x90 fs/ntfs/super.c:2656
write_inode fs/fs-writeback.c:1440 [inline]
__writeback_single_inode+0x614/0x1770 fs/fs-writeback.c:1652
writeback_sb_inodes+0x978/0x16c0 fs/fs-writeback.c:1878
wb_writeback+0x414/0x1130 fs/fs-writeback.c:2052
wb_do_writeback fs/fs-writeback.c:2195 [inline]
wb_workfn+0x3a8/0x1034 fs/fs-writeback.c:2235
process_one_work+0x7ac/0x1404 kernel/workqueue.c:2289
worker_thread+0x8e4/0xfec kernel/workqueue.c:2436
kthread+0x24c/0x2d4 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860