syzbot


possible deadlock in ocfs2_reserve_local_alloc_bits

Status: upstream: reported on 2025/06/17 01:40
Reported-by: syzbot+c234bcd0ae8845433ba8@syzkaller.appspotmail.com
First crash: 1d06h, last: 1d06h
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in ocfs2_reserve_local_alloc_bits ocfs2 C done 13612 15m 299d 0/28 upstream: reported C repro on 2024/08/22 12:35
linux-6.1 possible deadlock in ocfs2_reserve_local_alloc_bits origin:lts-only C inconclusive 1133 13h58m 263d 0/3 upstream: reported C repro on 2024/09/28 04:05
linux-5.15 possible deadlock in ocfs2_reserve_local_alloc_bits origin:lts-only C error 1086 10h11m 263d 0/3 upstream: reported C repro on 2024/09/27 17:46

Sample crash report:
loop6: detected capacity change from 0 to 32768
ocfs2: Slot 0 on device (7,6) was already allocated to this node!
ocfs2: Mounting device (7,6) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.6.93-syzkaller #0 Not tainted
------------------------------------------------------
syz.6.3526/14840 is trying to acquire lock:
ffff8880592309d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
ffff8880592309d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: ocfs2_reserve_local_alloc_bits+0x126/0x24b0 fs/ocfs2/localalloc.c:635

but task is already holding lock:
ffff8880749a14a0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_expand_inline_dir fs/ocfs2/dir.c:2820 [inline]
ffff8880749a14a0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_extend_dir+0x651/0x4760 fs/ocfs2/dir.c:3201

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}:
       down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
       ocfs2_try_remove_refcount_tree+0xb7/0x320 fs/ocfs2/refcounttree.c:932
       ocfs2_xattr_set+0x596/0x11f0 fs/ocfs2/xattr.c:3669
       ocfs2_set_acl+0x4e1/0x590 fs/ocfs2/acl.c:254
       ocfs2_iop_set_acl+0x1ab/0x2a0 fs/ocfs2/acl.c:286
       set_posix_acl fs/posix_acl.c:956 [inline]
       vfs_set_acl+0x803/0xa60 fs/posix_acl.c:1135
       do_setxattr fs/xattr.c:627 [inline]
       path_setxattr+0x39f/0x550 fs/xattr.c:659
       __do_sys_setxattr fs/xattr.c:677 [inline]
       __se_sys_setxattr fs/xattr.c:673 [inline]
       __x64_sys_setxattr+0xbb/0xd0 fs/xattr.c:673
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #4 (&oi->ip_xattr_sem){++++}-{3:3}:
       down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
       ocfs2_init_acl+0x2fa/0x720 fs/ocfs2/acl.c:366
       ocfs2_mknod+0x12e5/0x20f0 fs/ocfs2/namei.c:410
       ocfs2_create+0x196/0x410 fs/ocfs2/namei.c:674
       lookup_open fs/namei.c:3488 [inline]
       open_last_lookups fs/namei.c:3556 [inline]
       path_openat+0x1277/0x3190 fs/namei.c:3786
       do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
       do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
       do_sys_open fs/open.c:1434 [inline]
       __do_sys_openat fs/open.c:1450 [inline]
       __se_sys_openat fs/open.c:1445 [inline]
       __x64_sys_openat+0x139/0x160 fs/open.c:1445
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #3 (jbd2_handle){++++}-{0:0}:
       start_this_handle+0x1e9d/0x20c0 fs/jbd2/transaction.c:448
       jbd2__journal_start+0x2bb/0x5b0 fs/jbd2/transaction.c:505
       jbd2_journal_start+0x2a/0x40 fs/jbd2/transaction.c:544
       ocfs2_start_trans+0x376/0x6c0 fs/ocfs2/journal.c:374
       ocfs2_shutdown_local_alloc+0x201/0xa10 fs/ocfs2/localalloc.c:416
       ocfs2_dismount_volume+0x1e2/0x890 fs/ocfs2/super.c:1883
       generic_shutdown_super+0x134/0x2b0 fs/super.c:693
       kill_block_super+0x44/0x90 fs/super.c:1660
       deactivate_locked_super+0x97/0x100 fs/super.c:481
       cleanup_mnt+0x429/0x4c0 fs/namespace.c:1250
       task_work_run+0x1ce/0x250 kernel/task_work.c:239
       resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
       exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
       __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
       syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
       do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #2 (&journal->j_trans_barrier){.+.+}-{3:3}:
       down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
       ocfs2_start_trans+0x36a/0x6c0 fs/ocfs2/journal.c:372
       ocfs2_shutdown_local_alloc+0x201/0xa10 fs/ocfs2/localalloc.c:416
       ocfs2_dismount_volume+0x1e2/0x890 fs/ocfs2/super.c:1883
       generic_shutdown_super+0x134/0x2b0 fs/super.c:693
       kill_block_super+0x44/0x90 fs/super.c:1660
       deactivate_locked_super+0x97/0x100 fs/super.c:481
       cleanup_mnt+0x429/0x4c0 fs/namespace.c:1250
       task_work_run+0x1ce/0x250 kernel/task_work.c:239
       resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
       exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
       __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
       syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
       do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (sb_internal#4){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1633 [inline]
       sb_start_intwrite include/linux/fs.h:1755 [inline]
       ocfs2_start_trans+0x26b/0x6c0 fs/ocfs2/journal.c:370
       ocfs2_mknod+0xe47/0x20f0 fs/ocfs2/namei.c:361
       ocfs2_create+0x196/0x410 fs/ocfs2/namei.c:674
       lookup_open fs/namei.c:3488 [inline]
       open_last_lookups fs/namei.c:3556 [inline]
       path_openat+0x1277/0x3190 fs/namei.c:3786
       do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
       do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
       do_sys_open fs/open.c:1434 [inline]
       __do_sys_openat fs/open.c:1450 [inline]
       __se_sys_openat fs/open.c:1445 [inline]
       __x64_sys_openat+0x139/0x160 fs/open.c:1445
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
       lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
       down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:804 [inline]
       ocfs2_reserve_local_alloc_bits+0x126/0x24b0 fs/ocfs2/localalloc.c:635
       ocfs2_reserve_clusters_with_limit+0x1bf/0xba0 fs/ocfs2/suballoc.c:1162
       ocfs2_expand_inline_dir fs/ocfs2/dir.c:2856 [inline]
       ocfs2_extend_dir+0x702/0x4760 fs/ocfs2/dir.c:3201
       ocfs2_prepare_dir_for_insert+0x2fc7/0x5480 fs/ocfs2/dir.c:4322
       ocfs2_symlink+0xb38/0x2550 fs/ocfs2/namei.c:1863
       vfs_symlink+0x138/0x2b0 fs/namei.c:4473
       do_symlinkat+0x1b2/0x3f0 fs/namei.c:4499
       __do_sys_symlink fs/namei.c:4520 [inline]
       __se_sys_symlink fs/namei.c:4518 [inline]
       __x64_sys_symlink+0x7e/0x90 fs/namei.c:4518
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  &ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6 --> &oi->ip_xattr_sem --> &ocfs2_file_ip_alloc_sem_key

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_file_ip_alloc_sem_key);
                               lock(&oi->ip_xattr_sem);
                               lock(&ocfs2_file_ip_alloc_sem_key);
  lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6);

 *** DEADLOCK ***

3 locks held by syz.6.3526/14840:
 #0: ffff888030790418 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:403
 #1: ffff8880749a1818 (&type->i_mutex_dir_key#19/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
 #1: ffff8880749a1818 (&type->i_mutex_dir_key#19/1){+.+.}-{3:3}, at: filename_create+0x1f6/0x460 fs/namei.c:3882
 #2: ffff8880749a14a0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_expand_inline_dir fs/ocfs2/dir.c:2820 [inline]
 #2: ffff8880749a14a0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_extend_dir+0x651/0x4760 fs/ocfs2/dir.c:3201

stack backtrace:
CPU: 0 PID: 14840 Comm: syz.6.3526 Not tainted 6.6.93-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
 inode_lock include/linux/fs.h:804 [inline]
 ocfs2_reserve_local_alloc_bits+0x126/0x24b0 fs/ocfs2/localalloc.c:635
 ocfs2_reserve_clusters_with_limit+0x1bf/0xba0 fs/ocfs2/suballoc.c:1162
 ocfs2_expand_inline_dir fs/ocfs2/dir.c:2856 [inline]
 ocfs2_extend_dir+0x702/0x4760 fs/ocfs2/dir.c:3201
 ocfs2_prepare_dir_for_insert+0x2fc7/0x5480 fs/ocfs2/dir.c:4322
 ocfs2_symlink+0xb38/0x2550 fs/ocfs2/namei.c:1863
 vfs_symlink+0x138/0x2b0 fs/namei.c:4473
 do_symlinkat+0x1b2/0x3f0 fs/namei.c:4499
 __do_sys_symlink fs/namei.c:4520 [inline]
 __se_sys_symlink fs/namei.c:4518 [inline]
 __x64_sys_symlink+0x7e/0x90 fs/namei.c:4518
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f639d98e929
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:00007f639e7ed038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007f639dbb5fa0 RCX: 00007f639d98e929
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000200000000000
RBP: 00007f639da10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f639dbb5fa0 R15: 00007ffe4ece3ef8
 </TASK>
syz.6.3526 (14840) used greatest stack depth: 20336 bytes left

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/17 01:39 linux-6.6.y c2603c511feb cfebc887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in ocfs2_reserve_local_alloc_bits
2025/06/17 01:39 linux-6.6.y c2603c511feb cfebc887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in ocfs2_reserve_local_alloc_bits
* Struck through repros no longer work on HEAD.