syzbot


possible deadlock in ocfs2_mknod

Status: upstream: reported on 2025/06/08 23:15
Reported-by: syzbot+b741b33178eba66128cf@syzkaller.appspotmail.com
First crash: 33d, last: 31d

Sample crash report:
loop2: detected capacity change from 0 to 32768
ocfs2: Mounting device (7,2) on (node local, slot 0) with writeback data mode.
======================================================
WARNING: possible circular locking dependency detected
5.15.185-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.9/4295 is trying to acquire lock:
ffff88801afb4650 (sb_internal#3){.+.+}-{0:0}, at: ocfs2_mknod+0xe2f/0x22b0 fs/ocfs2/namei.c:361

but task is already holding lock:
ffff88805e7542c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
ffff88805e7542c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x161/0x4350 fs/ocfs2/suballoc.c:782

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}:
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       inode_lock include/linux/fs.h:787 [inline]
       ocfs2_reserve_suballoc_bits+0x161/0x4350 fs/ocfs2/suballoc.c:782
       ocfs2_reserve_cluster_bitmap_bits+0xc1/0x1c0 fs/ocfs2/suballoc.c:1128
       ocfs2_local_alloc_reserve_for_window fs/ocfs2/localalloc.c:1112 [inline]
       ocfs2_local_alloc_slide_window fs/ocfs2/localalloc.c:1248 [inline]
       ocfs2_reserve_local_alloc_bits+0x876/0x24c0 fs/ocfs2/localalloc.c:668
       ocfs2_reserve_clusters_with_limit+0x1bb/0xba0 fs/ocfs2/suballoc.c:1162
       ocfs2_reserve_clusters fs/ocfs2/suballoc.c:1223 [inline]
       ocfs2_lock_allocators+0x2f7/0x5b0 fs/ocfs2/suballoc.c:2669
       ocfs2_extend_allocation+0x397/0x1760 fs/ocfs2/file.c:588
       ocfs2_extend_no_holes+0x20b/0x490 fs/ocfs2/file.c:1030
       ocfs2_acquire_dquot+0x5fe/0xaf0 fs/ocfs2/quota_global.c:841
       dqget+0x778/0xeb0 fs/quota/dquot.c:988
       ocfs2_setattr+0xc93/0x1a10 fs/ocfs2/file.c:1236
       notify_change+0xbcd/0xee0 fs/attr.c:505
       chown_common+0x483/0x610 fs/open.c:680
       vfs_fchown fs/open.c:748 [inline]
       ksys_fchown+0xe2/0x150 fs/open.c:759
       __do_sys_fchown fs/open.c:767 [inline]
       __se_sys_fchown fs/open.c:765 [inline]
       __x64_sys_fchown+0x76/0x80 fs/open.c:765
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #7 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}:
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       inode_lock include/linux/fs.h:787 [inline]
       ocfs2_reserve_local_alloc_bits+0x122/0x24c0 fs/ocfs2/localalloc.c:635
       ocfs2_reserve_clusters_with_limit+0x1bb/0xba0 fs/ocfs2/suballoc.c:1162
       ocfs2_reserve_clusters fs/ocfs2/suballoc.c:1223 [inline]
       ocfs2_lock_allocators+0x2f7/0x5b0 fs/ocfs2/suballoc.c:2669
       ocfs2_extend_allocation+0x397/0x1760 fs/ocfs2/file.c:588
       ocfs2_extend_no_holes+0x20b/0x490 fs/ocfs2/file.c:1030
       ocfs2_acquire_dquot+0x5fe/0xaf0 fs/ocfs2/quota_global.c:841
       dqget+0x778/0xeb0 fs/quota/dquot.c:988
       ocfs2_setattr+0xc93/0x1a10 fs/ocfs2/file.c:1236
       notify_change+0xbcd/0xee0 fs/attr.c:505
       chown_common+0x483/0x610 fs/open.c:680
       vfs_fchown fs/open.c:748 [inline]
       ksys_fchown+0xe2/0x150 fs/open.c:759
       __do_sys_fchown fs/open.c:767 [inline]
       __se_sys_fchown fs/open.c:765 [inline]
       __x64_sys_fchown+0x76/0x80 fs/open.c:765
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #6 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}:
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       ocfs2_lock_global_qf+0x1e5/0x270 fs/ocfs2/quota_global.c:314
       ocfs2_acquire_dquot+0x29d/0xaf0 fs/ocfs2/quota_global.c:816
       dqget+0x778/0xeb0 fs/quota/dquot.c:988
       ocfs2_setattr+0xc93/0x1a10 fs/ocfs2/file.c:1236
       notify_change+0xbcd/0xee0 fs/attr.c:505
       chown_common+0x483/0x610 fs/open.c:680
       vfs_fchown fs/open.c:748 [inline]
       ksys_fchown+0xe2/0x150 fs/open.c:759
       __do_sys_fchown fs/open.c:767 [inline]
       __se_sys_fchown fs/open.c:765 [inline]
       __x64_sys_fchown+0x76/0x80 fs/open.c:765
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #5 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}:
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       inode_lock include/linux/fs.h:787 [inline]
       ocfs2_lock_global_qf+0x1c7/0x270 fs/ocfs2/quota_global.c:313
       ocfs2_acquire_dquot+0x29d/0xaf0 fs/ocfs2/quota_global.c:816
       dqget+0x778/0xeb0 fs/quota/dquot.c:988
       ocfs2_setattr+0xc93/0x1a10 fs/ocfs2/file.c:1236
       notify_change+0xbcd/0xee0 fs/attr.c:505
       chown_common+0x483/0x610 fs/open.c:680
       vfs_fchown fs/open.c:748 [inline]
       ksys_fchown+0xe2/0x150 fs/open.c:759
       __do_sys_fchown fs/open.c:767 [inline]
       __se_sys_fchown fs/open.c:765 [inline]
       __x64_sys_fchown+0x76/0x80 fs/open.c:765
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #4 (&dquot->dq_lock){+.+.}-{3:3}:
       __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       dquot_commit+0x5a/0x410 fs/quota/dquot.c:507
       ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6180
       mark_dquot_dirty fs/quota/dquot.c:372 [inline]
       mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412
       __dquot_alloc_space+0x5d0/0xe20 fs/quota/dquot.c:1752
       dquot_alloc_space_nodirty include/linux/quotaops.h:297 [inline]
       dquot_alloc_space include/linux/quotaops.h:310 [inline]
       dquot_alloc_block include/linux/quotaops.h:334 [inline]
       ext4_mb_new_blocks+0xf68/0x4940 fs/ext4/mballoc.c:5739
       ext4_ext_map_blocks+0x146c/0x64e0 fs/ext4/extents.c:4339
       ext4_map_blocks+0x981/0x1b30 fs/ext4/inode.c:673
       ext4_alloc_file_blocks+0x370/0xb50 fs/ext4/extents.c:4526
       ext4_zero_range+0x4b1/0xcf0 fs/ext4/extents.c:4643
       ext4_fallocate+0x540/0x1ee0 fs/ext4/extents.c:4778
       vfs_fallocate+0x587/0x6f0 fs/open.c:308
       ksys_fallocate fs/open.c:331 [inline]
       __do_sys_fallocate fs/open.c:339 [inline]
       __se_sys_fallocate fs/open.c:337 [inline]
       __x64_sys_fallocate+0xbd/0x100 fs/open.c:337
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #3 (&ei->i_data_sem){++++}-{3:3}:
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       ext4_truncate+0x96d/0x10d0 fs/ext4/inode.c:4245
       ext4_setattr+0xffe/0x19e0 fs/ext4/inode.c:5582
       notify_change+0xbcd/0xee0 fs/attr.c:505
       do_truncate+0x197/0x220 fs/open.c:65
       do_sys_ftruncate+0x31b/0x3d0 fs/open.c:193
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #2 (jbd2_handle){++++}-{0:0}:
       start_this_handle+0x1338/0x15a0 fs/jbd2/transaction.c:464
       jbd2__journal_start+0x2b7/0x5a0 fs/jbd2/transaction.c:521
       jbd2_journal_start+0x26/0x30 fs/jbd2/transaction.c:560
       ocfs2_start_trans+0x374/0x6c0 fs/ocfs2/journal.c:376
       ocfs2_modify_bh+0xe5/0x470 fs/ocfs2/quota_local.c:101
       ocfs2_local_read_info+0x13b1/0x16e0 fs/ocfs2/quota_local.c:764
       dquot_load_quota_sb+0x756/0xac0 fs/quota/dquot.c:2463
       dquot_load_quota_inode+0x2d8/0x5d0 fs/quota/dquot.c:2500
       ocfs2_enable_quotas+0x1c3/0x440 fs/ocfs2/super.c:927
       ocfs2_fill_super+0x3a1f/0x4d80 fs/ocfs2/super.c:1140
       mount_bdev+0x287/0x3c0 fs/super.c:1400
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x24a/0xa40 fs/namespace.c:3010
       do_mount fs/namespace.c:3353 [inline]
       __do_sys_mount fs/namespace.c:3561 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3538
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #1 (&journal->j_trans_barrier){.+.+}-{3:3}:
       down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498
       ocfs2_start_trans+0x368/0x6c0 fs/ocfs2/journal.c:374
       ocfs2_modify_bh+0xe5/0x470 fs/ocfs2/quota_local.c:101
       ocfs2_local_read_info+0x13b1/0x16e0 fs/ocfs2/quota_local.c:764
       dquot_load_quota_sb+0x756/0xac0 fs/quota/dquot.c:2463
       dquot_load_quota_inode+0x2d8/0x5d0 fs/quota/dquot.c:2500
       ocfs2_enable_quotas+0x1c3/0x440 fs/ocfs2/super.c:927
       ocfs2_fill_super+0x3a1f/0x4d80 fs/ocfs2/super.c:1140
       mount_bdev+0x287/0x3c0 fs/super.c:1400
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x24a/0xa40 fs/namespace.c:3010
       do_mount fs/namespace.c:3353 [inline]
       __do_sys_mount fs/namespace.c:3561 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3538
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (sb_internal#3){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
       lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1811 [inline]
       sb_start_intwrite include/linux/fs.h:1928 [inline]
       ocfs2_start_trans+0x269/0x6c0 fs/ocfs2/journal.c:372
       ocfs2_mknod+0xe2f/0x22b0 fs/ocfs2/namei.c:361
       ocfs2_create+0x192/0x410 fs/ocfs2/namei.c:674
       lookup_open fs/namei.c:3462 [inline]
       open_last_lookups fs/namei.c:3532 [inline]
       path_openat+0x11e1/0x2f30 fs/namei.c:3739
       do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
       do_sys_openat2+0x142/0x4a0 fs/open.c:1253
       do_sys_open fs/open.c:1269 [inline]
       __do_sys_openat fs/open.c:1285 [inline]
       __se_sys_openat fs/open.c:1280 [inline]
       __x64_sys_openat+0x135/0x160 fs/open.c:1280
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

Chain exists of:
  sb_internal#3 --> &ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4 --> &ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5);
                               lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4);
                               lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5);
  lock(sb_internal#3);

 *** DEADLOCK ***

5 locks held by syz.2.9/4295:
 #0: ffff88801afb4460 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:377
 #1: ffff88805e74ed88 (&type->i_mutex_dir_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88805e74ed88 (&type->i_mutex_dir_key#13){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3529 [inline]
 #1: ffff88805e74ed88 (&type->i_mutex_dir_key#13){+.+.}-{3:3}, at: path_openat+0x7f3/0x2f30 fs/namei.c:3739
 #2: ffff88805e756d88 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #2: ffff88805e756d88 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x161/0x4350 fs/ocfs2/suballoc.c:782
 #3: ffff88805e755f48 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #3: ffff88805e755f48 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x161/0x4350 fs/ocfs2/suballoc.c:782
 #4: ffff88805e7542c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #4: ffff88805e7542c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x161/0x4350 fs/ocfs2/suballoc.c:782

stack backtrace:
CPU: 0 PID: 4295 Comm: syz.2.9 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1811 [inline]
 sb_start_intwrite include/linux/fs.h:1928 [inline]
 ocfs2_start_trans+0x269/0x6c0 fs/ocfs2/journal.c:372
 ocfs2_mknod+0xe2f/0x22b0 fs/ocfs2/namei.c:361
 ocfs2_create+0x192/0x410 fs/ocfs2/namei.c:674
 lookup_open fs/namei.c:3462 [inline]
 open_last_lookups fs/namei.c:3532 [inline]
 path_openat+0x11e1/0x2f30 fs/namei.c:3739
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
 do_sys_openat2+0x142/0x4a0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1280
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fb2e4f30929
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:00007fb2e2d98038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb2e5157fa0 RCX: 00007fb2e4f30929
RDX: 00000000000c4042 RSI: 0000200000000300 RDI: ffffffffffffff9c
RBP: 00007fb2e4fb2b39 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000001ff R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb2e5157fa0 R15: 00007ffd378d4d28
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/08 23:14 linux-5.15.y 1c700860e8bc 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ocfs2_mknod
2025/06/10 21:18 linux-5.15.y 1c700860e8bc 5d7e17ca .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ocfs2_mknod
* Struck through repros no longer work on HEAD.