syzbot

NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
======================================================
WARNING: possible circular locking dependency detected
6.1.0-rc4-syzkaller-00020-gf67dd6ce0723 #0 Not tainted
------------------------------------------------------
syz-executor.3/12272 is trying to acquire lock:
ffff888074440090 (&nilfs->ns_sem){++++}-{3:3}, at: nilfs_set_error fs/nilfs2/super.c:92 [inline]
ffff888074440090 (&nilfs->ns_sem){++++}-{3:3}, at: __nilfs_error+0x1d2/0x4c0 fs/nilfs2/super.c:137

but task is already holding lock:
ffff888030195070 (&dat_lock_key){.+.+}-{3:3}, at: nilfs_get_block+0x1f7/0x8d0 fs/nilfs2/inode.c:84

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&dat_lock_key){.+.+}-{3:3}:
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
       down_read+0x39/0x50 kernel/locking/rwsem.c:1509
       nilfs_count_free_blocks+0x63/0x110 fs/nilfs2/the_nilfs.c:693
       nilfs_set_log_cursor fs/nilfs2/super.c:236 [inline]
       nilfs_cleanup_super+0x11e/0x410 fs/nilfs2/super.c:318
       nilfs_put_super+0x96/0x150 fs/nilfs2/super.c:472
       generic_shutdown_super+0x130/0x310 fs/super.c:492
       kill_block_super+0x79/0xd0 fs/super.c:1428
       deactivate_locked_super+0xa7/0xf0 fs/super.c:332
       cleanup_mnt+0x494/0x520 fs/namespace.c:1186
       task_work_run+0x243/0x300 kernel/task_work.c:179
       resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
       exit_to_user_mode_loop+0x124/0x150 kernel/entry/common.c:171
       exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:203
       __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
       syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:296
       do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&nilfs->ns_sem){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3097 [inline]
       check_prevs_add kernel/locking/lockdep.c:3216 [inline]
       validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
       __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
       down_write+0x9c/0x270 kernel/locking/rwsem.c:1562
       nilfs_set_error fs/nilfs2/super.c:92 [inline]
       __nilfs_error+0x1d2/0x4c0 fs/nilfs2/super.c:137
       nilfs_bmap_convert_error fs/nilfs2/bmap.c:35 [inline]
       nilfs_bmap_lookup_contig+0x132/0x150 fs/nilfs2/bmap.c:95
       nilfs_get_block+0x240/0x8d0 fs/nilfs2/inode.c:85
       do_mpage_readpage+0x970/0x1c50 fs/mpage.c:208
       mpage_readahead+0x210/0x380 fs/mpage.c:361
       read_pages+0x169/0x9c0 mm/readahead.c:161
       page_cache_ra_unbounded+0x703/0x820 mm/readahead.c:270
       page_cache_sync_readahead include/linux/pagemap.h:1213 [inline]
       filemap_get_pages+0x465/0x10d0 mm/filemap.c:2581
       filemap_read+0x3cf/0xea0 mm/filemap.c:2675
       __kernel_read+0x3fc/0x830 fs/read_write.c:428
       integrity_kernel_read+0xac/0xf0 security/integrity/iint.c:199
       ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:485 [inline]
       ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline]
       ima_calc_file_hash+0x178f/0x1ca0 security/integrity/ima/ima_crypto.c:573
       ima_collect_measurement+0x444/0x8c0 security/integrity/ima/ima_api.c:292
       process_measurement+0xf4b/0x1bd0 security/integrity/ima/ima_main.c:337
       ima_file_check+0xd8/0x130 security/integrity/ima/ima_main.c:517
       do_open fs/namei.c:3559 [inline]
       path_openat+0x2642/0x2df0 fs/namei.c:3713
       do_filp_open+0x264/0x4f0 fs/namei.c:3740
       do_sys_openat2+0x124/0x4e0 fs/open.c:1310
       do_sys_open fs/open.c:1326 [inline]
       __do_sys_open fs/open.c:1334 [inline]
       __se_sys_open fs/open.c:1330 [inline]
       __x64_sys_open+0x221/0x270 fs/open.c:1330
       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

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&dat_lock_key);
                               lock(&nilfs->ns_sem);
                               lock(&dat_lock_key);
  lock(&nilfs->ns_sem);

 *** DEADLOCK ***

4 locks held by syz-executor.3/12272:
 #0: ffff88807b8ac460 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
 #1: ffff88802d691aa0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x7ab/0x1bd0 security/integrity/ima/ima_main.c:260
 #2: ffff88803dcf4ac0 (mapping.invalidate_lock#3){.+.+}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:811 [inline]
 #2: ffff88803dcf4ac0 (mapping.invalidate_lock#3){.+.+}-{3:3}, at: page_cache_ra_unbounded+0xe9/0x820 mm/readahead.c:226
 #3: ffff888030195070 (&dat_lock_key){.+.+}-{3:3}, at: nilfs_get_block+0x1f7/0x8d0 fs/nilfs2/inode.c:84

stack backtrace:
CPU: 0 PID: 12272 Comm: syz-executor.3 Not tainted 6.1.0-rc4-syzkaller-00020-gf67dd6ce0723 #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+0x1b1/0x28e lib/dump_stack.c:106
 check_noncircular+0x2cc/0x390 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+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
 down_write+0x9c/0x270 kernel/locking/rwsem.c:1562
 nilfs_set_error fs/nilfs2/super.c:92 [inline]
 __nilfs_error+0x1d2/0x4c0 fs/nilfs2/super.c:137
 nilfs_bmap_convert_error fs/nilfs2/bmap.c:35 [inline]
 nilfs_bmap_lookup_contig+0x132/0x150 fs/nilfs2/bmap.c:95
 nilfs_get_block+0x240/0x8d0 fs/nilfs2/inode.c:85
 do_mpage_readpage+0x970/0x1c50 fs/mpage.c:208
 mpage_readahead+0x210/0x380 fs/mpage.c:361
 read_pages+0x169/0x9c0 mm/readahead.c:161
 page_cache_ra_unbounded+0x703/0x820 mm/readahead.c:270
 page_cache_sync_readahead include/linux/pagemap.h:1213 [inline]
 filemap_get_pages+0x465/0x10d0 mm/filemap.c:2581
 filemap_read+0x3cf/0xea0 mm/filemap.c:2675
 __kernel_read+0x3fc/0x830 fs/read_write.c:428
 integrity_kernel_read+0xac/0xf0 security/integrity/iint.c:199
 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:485 [inline]
 ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline]
 ima_calc_file_hash+0x178f/0x1ca0 security/integrity/ima/ima_crypto.c:573
 ima_collect_measurement+0x444/0x8c0 security/integrity/ima/ima_api.c:292
 process_measurement+0xf4b/0x1bd0 security/integrity/ima/ima_main.c:337
 ima_file_check+0xd8/0x130 security/integrity/ima/ima_main.c:517
 do_open fs/namei.c:3559 [inline]
 path_openat+0x2642/0x2df0 fs/namei.c:3713
 do_filp_open+0x264/0x4f0 fs/namei.c:3740
 do_sys_openat2+0x124/0x4e0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_open fs/open.c:1334 [inline]
 __se_sys_open fs/open.c:1330 [inline]
 __x64_sys_open+0x221/0x270 fs/open.c:1330
 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
RIP: 0033:0x7f1af6a8b639
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1af7719168 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f1af6babf80 RCX: 00007f1af6a8b639
RDX: 0000000000000030 RSI: 0000000000000282 RDI: 00000000200001c0
RBP: 00007f1af6ae67e1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe5354273f R14: 00007f1af7719300 R15: 0000000000022000
 </TASK>
Remounting filesystem read-only
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_lookup_contig: broken bmap (inode number=16)
NILFS (loop3): bad btree node (ino=16, blocknr=15): level = 0, flags = 0x9, nchildren = 0
NILFS error (device loop3): nilfs_bmap_last_key: broken bmap (inode number=16)
NILFS (loop3): error -5 truncating bmap (ino=16)
syz-executor.3 (12272) used greatest stack depth: 12632 bytes left