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possible deadlock in ocfs2_lock_refcount_tree (2)

Status: upstream: reported on 2025/01/09 03:59
Subsystems: ocfs2
[Documentation on labels]
Reported-by: syzbot+41cd2c009523c0f9f5b3@syzkaller.appspotmail.com
First crash: 41d, last: 11d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ocfs2?] possible deadlock in ocfs2_lock_refcount_tree (2) 0 (1) 2025/01/09 03:59
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 possible deadlock in ocfs2_lock_refcount_tree 35 3d20h 154d 0/3 upstream: reported on 2024/09/14 13:53
linux-6.1 possible deadlock in ocfs2_lock_refcount_tree 23 2d00h 96d 0/3 upstream: reported on 2024/11/11 19:23
upstream possible deadlock in ocfs2_lock_refcount_tree ocfs2 5 145d 162d 0/28 auto-obsoleted due to no activity on 2025/01/01 02:27

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc1-syzkaller-00026-gd009de7d5428 #0 Not tainted
------------------------------------------------------
syz.5.484/10675 is trying to acquire lock:
ffff888029308898 (&new->rf_sem){+.+.}-{4:4}, at: __ocfs2_lock_refcount_tree fs/ocfs2/refcounttree.c:428 [inline]
ffff888029308898 (&new->rf_sem){+.+.}-{4:4}, at: ocfs2_lock_refcount_tree+0x1fe/0xa70 fs/ocfs2/refcounttree.c:463

but task is already holding lock:
ffff88805d18ea20 (&ocfs2_quota_ip_alloc_sem_key){++++}-{4:4}, at: ocfs2_truncate_file+0x380/0x1560 fs/ocfs2/file.c:471

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #7 (&ocfs2_quota_ip_alloc_sem_key){++++}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       ocfs2_lock_global_qf+0x225/0x2b0 fs/ocfs2/quota_global.c:314
       ocfs2_acquire_dquot+0x2b0/0xb70 fs/ocfs2/quota_global.c:828
       dqget+0x770/0xeb0 fs/quota/dquot.c:977
       __dquot_initialize+0x2e3/0xec0 fs/quota/dquot.c:1505
       ocfs2_get_init_inode+0x158/0x1d0 fs/ocfs2/namei.c:202
       ocfs2_mknod+0xcfa/0x2b30 fs/ocfs2/namei.c:310
       ocfs2_mkdir+0x1ab/0x470 fs/ocfs2/namei.c:656
       vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4313
       do_mkdirat+0x264/0x3a0 fs/namei.c:4336
       __do_sys_mkdirat fs/namei.c:4351 [inline]
       __se_sys_mkdirat fs/namei.c:4349 [inline]
       __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4349
       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

-> #6 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       inode_lock include/linux/fs.h:865 [inline]
       ocfs2_lock_global_qf+0x206/0x2b0 fs/ocfs2/quota_global.c:313
       ocfs2_acquire_dquot+0x2b0/0xb70 fs/ocfs2/quota_global.c:828
       dqget+0x770/0xeb0 fs/quota/dquot.c:977
       __dquot_initialize+0x2e3/0xec0 fs/quota/dquot.c:1505
       ocfs2_get_init_inode+0x158/0x1d0 fs/ocfs2/namei.c:202
       ocfs2_mknod+0xcfa/0x2b30 fs/ocfs2/namei.c:310
       ocfs2_mkdir+0x1ab/0x470 fs/ocfs2/namei.c:656
       vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4313
       do_mkdirat+0x264/0x3a0 fs/namei.c:4336
       __do_sys_mkdirat fs/namei.c:4351 [inline]
       __se_sys_mkdirat fs/namei.c:4349 [inline]
       __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4349
       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

-> #5 (&dquot->dq_lock){+.+.}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730
       wait_on_dquot fs/quota/dquot.c:354 [inline]
       dqget+0x6e6/0xeb0 fs/quota/dquot.c:972
       __dquot_initialize+0x468/0xec0 fs/quota/dquot.c:1505
       __ext4_new_inode+0x852/0x4630 fs/ext4/ialloc.c:992
       ext4_xattr_inode_create fs/ext4/xattr.c:1486 [inline]
       ext4_xattr_inode_lookup_create+0x99e/0x1c90 fs/ext4/xattr.c:1596
       ext4_xattr_block_set+0x272/0x3160 fs/ext4/xattr.c:1916
       ext4_xattr_set_handle+0xce0/0x1580 fs/ext4/xattr.c:2458
       ext4_initxattrs+0xa3/0x120 fs/ext4/xattr_security.c:44
       security_inode_init_security+0x29c/0x480 security/security.c:1852
       __ext4_new_inode+0x388f/0x4630 fs/ext4/ialloc.c:1324
       ext4_mkdir+0x425/0xcf0 fs/ext4/namei.c:3024
       vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4313
       do_mkdirat+0x264/0x3a0 fs/namei.c:4336
       __do_sys_mkdirat fs/namei.c:4351 [inline]
       __se_sys_mkdirat fs/namei.c:4349 [inline]
       __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4349
       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

-> #4 (&ei->xattr_sem){++++}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       ext4_write_lock_xattr fs/ext4/xattr.h:154 [inline]
       ext4_xattr_set_handle+0x277/0x1580 fs/ext4/xattr.c:2373
       ext4_initxattrs+0xa3/0x120 fs/ext4/xattr_security.c:44
       security_inode_init_security+0x29c/0x480 security/security.c:1852
       __ext4_new_inode+0x388f/0x4630 fs/ext4/ialloc.c:1324
       ext4_create+0x279/0x550 fs/ext4/namei.c:2841
       lookup_open fs/namei.c:3651 [inline]
       open_last_lookups fs/namei.c:3750 [inline]
       path_openat+0x193c/0x3590 fs/namei.c:3986
       do_filp_open+0x27f/0x4e0 fs/namei.c:4016
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1427
       do_sys_open fs/open.c:1442 [inline]
       __do_sys_openat fs/open.c:1458 [inline]
       __se_sys_openat fs/open.c:1453 [inline]
       __x64_sys_openat+0x247/0x2a0 fs/open.c:1453
       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

-> #3 (jbd2_handle){++++}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       start_this_handle+0x1eb4/0x2110 fs/jbd2/transaction.c:448
       jbd2__journal_start+0x2da/0x5d0 fs/jbd2/transaction.c:505
       jbd2_journal_start+0x29/0x40 fs/jbd2/transaction.c:544
       ocfs2_start_trans+0x3c9/0x700 fs/ocfs2/journal.c:352
       ocfs2_modify_bh+0xed/0x4d0 fs/ocfs2/quota_local.c:101
       ocfs2_local_read_info+0x158f/0x19f0 fs/ocfs2/quota_local.c:771
       dquot_load_quota_sb+0x762/0xbb0 fs/quota/dquot.c:2459
       dquot_load_quota_inode+0x320/0x600 fs/quota/dquot.c:2496
       ocfs2_enable_quotas+0x169/0x450 fs/ocfs2/super.c:930
       ocfs2_fill_super+0x5ade/0x7200 fs/ocfs2/super.c:1140
       get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
       vfs_get_tree+0x90/0x2b0 fs/super.c:1814
       do_new_mount+0x2be/0xb40 fs/namespace.c:3560
       do_mount fs/namespace.c:3900 [inline]
       __do_sys_mount fs/namespace.c:4111 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
       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

-> #2 (&journal->j_trans_barrier){.+.+}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
       ocfs2_start_trans+0x3be/0x700 fs/ocfs2/journal.c:350
       ocfs2_modify_bh+0xed/0x4d0 fs/ocfs2/quota_local.c:101
       ocfs2_local_read_info+0x158f/0x19f0 fs/ocfs2/quota_local.c:771
       dquot_load_quota_sb+0x762/0xbb0 fs/quota/dquot.c:2459
       dquot_load_quota_inode+0x320/0x600 fs/quota/dquot.c:2496
       ocfs2_enable_quotas+0x169/0x450 fs/ocfs2/super.c:930
       ocfs2_fill_super+0x5ade/0x7200 fs/ocfs2/super.c:1140
       get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
       vfs_get_tree+0x90/0x2b0 fs/super.c:1814
       do_new_mount+0x2be/0xb40 fs/namespace.c:3560
       do_mount fs/namespace.c:3900 [inline]
       __do_sys_mount fs/namespace.c:4111 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
       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 (sb_internal#3){.+.+}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1773 [inline]
       sb_start_intwrite include/linux/fs.h:1956 [inline]
       ocfs2_start_trans+0x2b9/0x700 fs/ocfs2/journal.c:348
       ocfs2_set_refcount_tree+0x29e/0x850 fs/ocfs2/refcounttree.c:713
       ocfs2_reflink_remap_blocks+0x66f/0x1f30 fs/ocfs2/refcounttree.c:4663
       ocfs2_remap_file_range+0x5fa/0x8d0 fs/ocfs2/file.c:2740
       vfs_copy_file_range+0xc07/0x14f0 fs/read_write.c:1584
       __do_sys_copy_file_range fs/read_write.c:1670 [inline]
       __se_sys_copy_file_range+0x3fa/0x600 fs/read_write.c:1637
       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 (&new->rf_sem){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       __ocfs2_lock_refcount_tree fs/ocfs2/refcounttree.c:428 [inline]
       ocfs2_lock_refcount_tree+0x1fe/0xa70 fs/ocfs2/refcounttree.c:463
       ocfs2_refcount_cow_hunk fs/ocfs2/refcounttree.c:3406 [inline]
       ocfs2_refcount_cow+0x763/0x11a0 fs/ocfs2/refcounttree.c:3467
       ocfs2_cow_file_pos+0x3b2/0x4b0 fs/ocfs2/file.c:366
       ocfs2_orphan_for_truncate fs/ocfs2/file.c:387 [inline]
       ocfs2_truncate_file+0x3da/0x1560 fs/ocfs2/file.c:500
       ocfs2_setattr+0x1890/0x1ef0 fs/ocfs2/file.c:1212
       notify_change+0xbca/0xe90 fs/attr.c:552
       do_truncate+0x220/0x310 fs/open.c:65
       vfs_truncate+0x492/0x530 fs/open.c:115
       do_sys_truncate+0xdb/0x190 fs/open.c:138
       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:
  &new->rf_sem --> &ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7 --> &ocfs2_quota_ip_alloc_sem_key

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_quota_ip_alloc_sem_key);
                               lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7);
                               lock(&ocfs2_quota_ip_alloc_sem_key);
  lock(&new->rf_sem);

 *** DEADLOCK ***

3 locks held by syz.5.484/10675:
 #0: ffff88804f68e420 (sb_writers#30){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:547
 #1: ffff88805d18ed80 (&sb->s_type->i_mutex_key#36){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:865 [inline]
 #1: ffff88805d18ed80 (&sb->s_type->i_mutex_key#36){+.+.}-{4:4}, at: do_truncate+0x20c/0x310 fs/open.c:63
 #2: ffff88805d18ea20 (&ocfs2_quota_ip_alloc_sem_key){++++}-{4:4}, at: ocfs2_truncate_file+0x380/0x1560 fs/ocfs2/file.c:471

stack backtrace:
CPU: 1 UID: 0 PID: 10675 Comm: syz.5.484 Not tainted 6.14.0-rc1-syzkaller-00026-gd009de7d5428 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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:2076
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 down_write+0x99/0x220 kernel/locking/rwsem.c:1577
 __ocfs2_lock_refcount_tree fs/ocfs2/refcounttree.c:428 [inline]
 ocfs2_lock_refcount_tree+0x1fe/0xa70 fs/ocfs2/refcounttree.c:463
 ocfs2_refcount_cow_hunk fs/ocfs2/refcounttree.c:3406 [inline]
 ocfs2_refcount_cow+0x763/0x11a0 fs/ocfs2/refcounttree.c:3467
 ocfs2_cow_file_pos+0x3b2/0x4b0 fs/ocfs2/file.c:366
 ocfs2_orphan_for_truncate fs/ocfs2/file.c:387 [inline]
 ocfs2_truncate_file+0x3da/0x1560 fs/ocfs2/file.c:500
 ocfs2_setattr+0x1890/0x1ef0 fs/ocfs2/file.c:1212
 notify_change+0xbca/0xe90 fs/attr.c:552
 do_truncate+0x220/0x310 fs/open.c:65
 vfs_truncate+0x492/0x530 fs/open.c:115
 do_sys_truncate+0xdb/0x190 fs/open.c:138
 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: 0033:0x7fabecf8cde9
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:00007fabedd6d038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007fabed1a6160 RCX: 00007fabecf8cde9
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000200000000280
RBP: 00007fabed00e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fabed1a6160 R15: 00007ffdafa2d6d8
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/05 00:37 upstream d009de7d5428 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_lock_refcount_tree
2025/01/05 03:55 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 573067a5a685 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in ocfs2_lock_refcount_tree
* Struck through repros no longer work on HEAD.