* possible deadlock in ocfs2_reserve_local_alloc_bits
@ 2026-06-26 21:28 sanan.hasanou
0 siblings, 0 replies; only message in thread
From: sanan.hasanou @ 2026-06-26 21:28 UTC (permalink / raw)
To: mark, jlbec, joseph.qi, ocfs2-devel, linux-kernel; +Cc: syzkaller, contact
Good day, dear maintainers,
We found a bug using a modified version of syzkaller.
Kernel Branch: 7.0-rc1
Kernel Config: <https://drive.google.com/open?id=1pN21FuDB9QSbn_3jaZGO1S5v7x7Qe-yl>
Reproducer: <https://drive.google.com/open?id=1ImQo8kSKiuXjxNHmTGYAguyy132NdzzR>
Thank you!
Best regards,
Sanan Hasanov
ocfs2: Mounting device (7,2) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
7.0.0-rc1 #1 Not tainted
------------------------------------------------------
syz.2.9439/46503 is trying to acquire lock:
ffff88803c839800 (&ocfs2_sysfile_lock_key[LOCAL_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
ffff88803c839800 (&ocfs2_sysfile_lock_key[LOCAL_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_local_alloc_bits+0x12a/0x2980 fs/ocfs2/localalloc.c:636
but task is already holding lock:
ffff88802ced6a20 (&ocfs2_file_ip_alloc_sem_key){++++}-{4:4}, at: ocfs2_expand_inline_dir fs/ocfs2/dir.c:2846 [inline]
ffff88802ced6a20 (&ocfs2_file_ip_alloc_sem_key){++++}-{4:4}, at: ocfs2_extend_dir+0x623/0x4780 fs/ocfs2/dir.c:3227
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&ocfs2_file_ip_alloc_sem_key){++++}-{4:4}:
down_write+0x96/0x1e0 kernel/locking/rwsem.c:1590
ocfs2_try_remove_refcount_tree+0xb6/0x320 fs/ocfs2/refcounttree.c:933
ocfs2_xattr_set+0x5c1/0x1220 fs/ocfs2/xattr.c:3700
ocfs2_set_acl+0x701/0x7b0 fs/ocfs2/acl.c:255
ocfs2_iop_set_acl+0x1aa/0x2a0 fs/ocfs2/acl.c:287
set_posix_acl fs/posix_acl.c:955 [inline]
vfs_set_acl+0x8f9/0xbf0 fs/posix_acl.c:1134
do_setxattr fs/xattr.c:633 [inline]
filename_setxattr+0x2f4/0x610 fs/xattr.c:664
path_setxattrat+0x356/0x3a0 fs/xattr.c:708
__do_sys_setxattr fs/xattr.c:742 [inline]
__se_sys_setxattr fs/xattr.c:738 [inline]
__x64_sys_setxattr+0xbc/0xd0 fs/xattr.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x11c/0x800 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x4b/0x53
-> #3 (&oi->ip_xattr_sem){++++}-{4:4}:
down_read+0x97/0x2c0 kernel/locking/rwsem.c:1537
ocfs2_init_acl+0x2f7/0x7a0 fs/ocfs2/acl.c:367
ocfs2_mknod+0x128d/0x20d0 fs/ocfs2/namei.c:414
ocfs2_create+0x160/0x3e0 fs/ocfs2/namei.c:677
lookup_open fs/namei.c:4483 [inline]
open_last_lookups fs/namei.c:4583 [inline]
path_openat+0x1388/0x3730 fs/namei.c:4827
do_file_open+0x203/0x440 fs/namei.c:4859
do_sys_openat2+0x105/0x1d0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x160 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x11c/0x800 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x4b/0x53
-> #2 (&journal->j_trans_barrier){.+.+}-{4:4}:
down_read+0x97/0x2c0 kernel/locking/rwsem.c:1537
ocfs2_start_trans+0x36a/0x6d0 fs/ocfs2/journal.c:369
ocfs2_modify_bh+0xe8/0x470 fs/ocfs2/quota_local.c:101
ocfs2_local_read_info+0x1460/0x17e0 fs/ocfs2/quota_local.c:767
dquot_load_quota_sb+0x78b/0xba0 fs/quota/dquot.c:2462
dquot_load_quota_inode+0x2dc/0x5d0 fs/quota/dquot.c:2499
ocfs2_enable_quotas+0x1c6/0x440 fs/ocfs2/super.c:930
ocfs2_fill_super+0x5085/0x6370 fs/ocfs2/super.c:1140
get_tree_bdev_flags+0x402/0x4c0 fs/super.c:1694
vfs_get_tree+0x8d/0x1d0 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3760 [inline]
do_new_mount+0x31a/0xce0 fs/namespace.c:3836
do_mount fs/namespace.c:4159 [inline]
__do_sys_mount fs/namespace.c:4348 [inline]
__se_sys_mount+0x313/0x400 fs/namespace.c:4325
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x11c/0x800 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x4b/0x53
-> #1 (sb_internal#3){.+.+}-{0:0}:
percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_intwrite include/linux/fs/super.h:177 [inline]
ocfs2_start_trans+0x26b/0x6d0 fs/ocfs2/journal.c:367
ocfs2_mknod+0xdfb/0x20d0 fs/ocfs2/namei.c:365
ocfs2_create+0x160/0x3e0 fs/ocfs2/namei.c:677
lookup_open fs/namei.c:4483 [inline]
open_last_lookups fs/namei.c:4583 [inline]
path_openat+0x1388/0x3730 fs/namei.c:4827
do_file_open+0x203/0x440 fs/namei.c:4859
do_sys_openat2+0x105/0x1d0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x160 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x11c/0x800 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x4b/0x53
-> #0 (&ocfs2_sysfile_lock_key[LOCAL_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x1591/0x2870 kernel/locking/lockdep.c:5237
lock_acquire+0xe0/0x290 kernel/locking/lockdep.c:5868
down_write+0x96/0x1e0 kernel/locking/rwsem.c:1590
inode_lock include/linux/fs.h:1028 [inline]
ocfs2_reserve_local_alloc_bits+0x12a/0x2980 fs/ocfs2/localalloc.c:636
ocfs2_reserve_clusters_with_limit+0x1be/0xba0 fs/ocfs2/suballoc.c:1237
ocfs2_expand_inline_dir fs/ocfs2/dir.c:2882 [inline]
ocfs2_extend_dir+0x6dd/0x4780 fs/ocfs2/dir.c:3227
ocfs2_prepare_dir_for_insert+0x3080/0x4e90 fs/ocfs2/dir.c:4345
ocfs2_symlink+0xb13/0x2520 fs/ocfs2/namei.c:1876
vfs_symlink+0x18a/0x330 fs/namei.c:5615
filename_symlinkat+0x19c/0x3e0 fs/namei.c:5640
__do_sys_symlink fs/namei.c:5667 [inline]
__se_sys_symlink+0x4d/0x280 fs/namei.c:5663
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x11c/0x800 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x4b/0x53
other info that might help us debug this:
Chain exists of:
&ocfs2_sysfile_lock_key[LOCAL_ALLOC_SYSTEM_INODE] --> &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[LOCAL_ALLOC_SYSTEM_INODE]);
*** DEADLOCK ***
3 locks held by syz.2.9439/46503:
#0: ffff88801c57e410 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff88802ced6d80 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff88802ced6d80 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline]
#1: ffff88802ced6d80 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline]
#1: ffff88802ced6d80 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: filename_create+0x1fb/0x360 fs/namei.c:4922
#2: ffff88802ced6a20 (&ocfs2_file_ip_alloc_sem_key){++++}-{4:4}, at: ocfs2_expand_inline_dir fs/ocfs2/dir.c:2846 [inline]
#2: ffff88802ced6a20 (&ocfs2_file_ip_alloc_sem_key){++++}-{4:4}, at: ocfs2_extend_dir+0x623/0x4780 fs/ocfs2/dir.c:3227
stack backtrace:
CPU: 0 UID: 0 PID: 46503 Comm: syz.2.9439 Not tainted 7.0.0-rc1 #1 PREEMPT(full)
Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2f8/0x340 kernel/locking/lockdep.c:2043
check_noncircular+0x109/0x130 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x1591/0x2870 kernel/locking/lockdep.c:5237
lock_acquire+0xe0/0x290 kernel/locking/lockdep.c:5868
down_write+0x96/0x1e0 kernel/locking/rwsem.c:1590
inode_lock include/linux/fs.h:1028 [inline]
ocfs2_reserve_local_alloc_bits+0x12a/0x2980 fs/ocfs2/localalloc.c:636
ocfs2_reserve_clusters_with_limit+0x1be/0xba0 fs/ocfs2/suballoc.c:1237
ocfs2_expand_inline_dir fs/ocfs2/dir.c:2882 [inline]
ocfs2_extend_dir+0x6dd/0x4780 fs/ocfs2/dir.c:3227
ocfs2_prepare_dir_for_insert+0x3080/0x4e90 fs/ocfs2/dir.c:4345
ocfs2_symlink+0xb13/0x2520 fs/ocfs2/namei.c:1876
vfs_symlink+0x18a/0x330 fs/namei.c:5615
filename_symlinkat+0x19c/0x3e0 fs/namei.c:5640
__do_sys_symlink fs/namei.c:5667 [inline]
__se_sys_symlink+0x4d/0x280 fs/namei.c:5663
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x11c/0x800 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f9e2e9a3b6d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9e2f830018 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007f9e2ec15fa0 RCX: 00007f9e2e9a3b6d
RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000200000000300
RBP: 00007f9e2ea47c3e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9e2ec16038 R14: 00007f9e2ec15fa0 R15: 00007fff50e045a0
</TASK>
syz.2.9439 (46503) used greatest stack depth: 19688 bytes left
<<<<<<<<<<<<<<< tail report >>>>>>>>>>>>>>>
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2026-06-26 21:28 possible deadlock in ocfs2_reserve_local_alloc_bits sanan.hasanou
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