syzbot


possible deadlock in map_mft_record

Status: upstream: reported on 2022/10/19 05:29
Reported-by: syzbot+cb1fdea540b46f0ce394@syzkaller.appspotmail.com
First crash: 39d, last: 1d06h
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 possible deadlock in map_mft_record 1 12d 12d 0/1 upstream: reported on 2022/11/15 01:41
linux-4.19 possible deadlock in map_mft_record 4 18d 48d 0/1 upstream: reported on 2022/10/09 19:52

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.1.0-rc6-syzkaller-00251-g0b1dcc2cf55a #0 Not tainted
------------------------------------------------------
syz-executor.2/8673 is trying to acquire lock:
ffff88804db05410 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x46/0x610 fs/ntfs/mft.c:154

but task is already holding lock:
ffff88804db05380 (&rl->lock){++++}-{3:3}, at: ntfs_truncate+0x1e8/0x2740 fs/ntfs/inode.c:2378

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&rl->lock){++++}-{3:3}:
       lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5668
       down_read+0x39/0x50 kernel/locking/rwsem.c:1509
       ntfs_read_block+0x96e/0x2440 fs/ntfs/aops.c:248
       filemap_read_folio+0x1ba/0x7f0 mm/filemap.c:2407
       do_read_cache_folio+0x2d3/0x790 mm/filemap.c:3534
       do_read_cache_page mm/filemap.c:3576 [inline]
       read_cache_page+0x56/0x270 mm/filemap.c:3585
       read_mapping_page include/linux/pagemap.h:756 [inline]
       ntfs_map_page fs/ntfs/aops.h:75 [inline]
       ntfs_sync_mft_mirror+0x253/0x1e30 fs/ntfs/mft.c:480
       write_mft_record_nolock+0x13f1/0x1970 fs/ntfs/mft.c:787
       write_mft_record fs/ntfs/mft.h:95 [inline]
       __ntfs_write_inode+0x721/0xc90 fs/ntfs/inode.c:3050
       write_inode fs/fs-writeback.c:1440 [inline]
       __writeback_single_inode+0x4d6/0x670 fs/fs-writeback.c:1652
       writeback_sb_inodes+0xb45/0x18c0 fs/fs-writeback.c:1878
       wb_writeback+0x43c/0x7a0 fs/fs-writeback.c:2052
       wb_do_writeback fs/fs-writeback.c:2195 [inline]
       wb_workfn+0x3cb/0xf10 fs/fs-writeback.c:2235
       process_one_work+0x81c/0xd10 kernel/workqueue.c:2289
       worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
       kthread+0x266/0x300 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

-> #0 (&ni->mrec_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3097 [inline]
       check_prevs_add kernel/locking/lockdep.c:3216 [inline]
       validate_chain+0x184a/0x6470 kernel/locking/lockdep.c:3831
       __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
       lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5668
       __mutex_lock_common+0x1de/0x26c0 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+0x46/0x610 fs/ntfs/mft.c:154
       ntfs_truncate+0x25e/0x2740 fs/ntfs/inode.c:2383
       ntfs_truncate_vfs fs/ntfs/inode.c:2862 [inline]
       ntfs_setattr+0x2b9/0x3a0 fs/ntfs/inode.c:2914
       notify_change+0xe38/0x10f0 fs/attr.c:420
       do_truncate+0x214/0x300 fs/open.c:65
       handle_truncate fs/namei.c:3216 [inline]
       do_open fs/namei.c:3561 [inline]
       path_openat+0x2782/0x2e00 fs/namei.c:3714
       do_filp_open+0x275/0x500 fs/namei.c:3741
       do_sys_openat2+0x13b/0x500 fs/open.c:1310
       do_sys_open fs/open.c:1326 [inline]
       __do_sys_creat fs/open.c:1402 [inline]
       __se_sys_creat fs/open.c:1396 [inline]
       __x64_sys_creat+0x11f/0x160 fs/open.c:1396
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

3 locks held by syz-executor.2/8673:
 #0: ffff888056836460 (sb_writers#31){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
 #1: ffff88804db056f0 (&sb->s_type->i_mutex_key#40){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
 #1: ffff88804db056f0 (&sb->s_type->i_mutex_key#40){+.+.}-{3:3}, at: do_truncate+0x200/0x300 fs/open.c:63
 #2: ffff88804db05380 (&rl->lock){++++}-{3:3}, at: ntfs_truncate+0x1e8/0x2740 fs/ntfs/inode.c:2378

stack backtrace:
CPU: 1 PID: 8673 Comm: syz-executor.2 Not tainted 6.1.0-rc6-syzkaller-00251-g0b1dcc2cf55a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2f9/0x3b0 kernel/locking/lockdep.c:2177
 check_prev_add kernel/locking/lockdep.c:3097 [inline]
 check_prevs_add kernel/locking/lockdep.c:3216 [inline]
 validate_chain+0x184a/0x6470 kernel/locking/lockdep.c:3831
 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5668
 __mutex_lock_common+0x1de/0x26c0 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+0x46/0x610 fs/ntfs/mft.c:154
 ntfs_truncate+0x25e/0x2740 fs/ntfs/inode.c:2383
 ntfs_truncate_vfs fs/ntfs/inode.c:2862 [inline]
 ntfs_setattr+0x2b9/0x3a0 fs/ntfs/inode.c:2914
 notify_change+0xe38/0x10f0 fs/attr.c:420
 do_truncate+0x214/0x300 fs/open.c:65
 handle_truncate fs/namei.c:3216 [inline]
 do_open fs/namei.c:3561 [inline]
 path_openat+0x2782/0x2e00 fs/namei.c:3714
 do_filp_open+0x275/0x500 fs/namei.c:3741
 do_sys_openat2+0x13b/0x500 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_creat fs/open.c:1402 [inline]
 __se_sys_creat fs/open.c:1396 [inline]
 __x64_sys_creat+0x11f/0x160 fs/open.c:1396
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f031448c0d9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0315270168 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f03145abf80 RCX: 00007f031448c0d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200000c0
RBP: 00007f03144e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff1afbc69f R14: 00007f0315270300 R15: 0000000000022000
 </TASK>

Crashes (10):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2022/11/25 20:19 upstream 0b1dcc2cf55a 74a66371 .config log report info possible deadlock in map_mft_record
ci2-upstream-fs 2022/11/24 12:59 upstream 4312098baf37 ff68ff8f .config log report info possible deadlock in map_mft_record
ci2-upstream-fs 2022/11/18 10:50 upstream 84368d882b96 5bb70014 .config log report info possible deadlock in map_mft_record
ci-qemu-upstream 2022/11/14 16:48 upstream 094226ad94f4 943f4cb8 .config log report info possible deadlock in map_mft_record
ci2-upstream-fs 2022/11/13 10:40 upstream fef7fd48922d f42ee5d8 .config log report info possible deadlock in map_mft_record
ci-upstream-kasan-gce-root 2022/11/10 19:27 upstream 1767a722a708 3ead01ad .config log report info possible deadlock in map_mft_record
ci2-upstream-fs 2022/11/08 18:57 upstream 59f2f4b8a757 060f945e .config log report info possible deadlock in map_mft_record
ci2-upstream-fs 2022/11/08 18:17 upstream 59f2f4b8a757 060f945e .config log report info possible deadlock in map_mft_record
ci-qemu-upstream-386 2022/11/22 21:40 upstream eb7081409f94 1c8e10bc .config log report info possible deadlock in map_mft_record
ci-upstream-gce-arm64 2022/10/18 16:52 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci bbed346d5a96 b31320fc .config log report info possible deadlock in map_mft_record
* Struck through repros no longer work on HEAD.