syzbot
possible deadlock in ocfs2_xattr_set_handle (2)
Status:
upstream: reported on 2026/10/15 07:48
Subsystems:
ocfs2
Labels:
prio:high
[Documentation on labels]
Reported-by: syzbot+b4732eab3dcd27c32ae6@syzkaller.appspotmail.com
First crash: 4d07h, last: 4d07h
Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G Y
------------------------------------------------------
syz.1.1388/11252 is trying to acquire lock:
ffff88805079b058 (&oi->ip_alloc_sem/1){+.+.}-{4:4}, at: ocfs2_xattr_set_handle+0x3fc/0x820 fs/ocfs2/xattr.c:3888
but task is already holding lock:
ffff888036ee0ce0 (&journal->j_trans_barrier){.+.+}-{4:4}, at: ocfs2_start_trans+0x3a9/0x6f0 fs/ocfs2/journal.c:370
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&journal->j_trans_barrier){.+.+}-{4:4}:
down_read+0x45/0x320 kernel/locking/rwsem.c:1574
ocfs2_start_trans+0x3a9/0x6f0 fs/ocfs2/journal.c:370
ocfs2_mknod+0xf07/0x2190 fs/ocfs2/namei.c:364
ocfs2_create+0x195/0x460 fs/ocfs2/namei.c:677
lookup_open+0xedc/0x1970 fs/namei.c:4598
open_last_lookups fs/namei.c:4798 [inline]
path_openat+0x673/0x1da0 fs/namei.c:5037
do_file_open+0x23e/0x4a0 fs/namei.c:5069
do_sys_openat2+0x115/0x200 fs/open.c:1442
do_sys_open fs/open.c:1448 [inline]
__do_sys_open fs/open.c:1780 [inline]
__se_sys_open fs/open.c:1776 [inline]
__x64_sys_open+0x11e/0x150 fs/open.c:1776
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (sb_internal#4){.+.+}-{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+0x2a7/0x6f0 fs/ocfs2/journal.c:368
ocfs2_duplicate_inline_data+0x16a/0x570 fs/ocfs2/refcounttree.c:3988
ocfs2_reflink_remap_blocks+0x4aa/0x1ab0 fs/ocfs2/refcounttree.c:4681
ocfs2_remap_file_range+0x451/0x6f0 fs/ocfs2/file.c:2752
vfs_copy_file_range+0xd70/0x1340 fs/read_write.c:2309
__do_sys_copy_file_range fs/read_write.c:2392 [inline]
__se_sys_copy_file_range+0x2fb/0x480 fs/read_write.c:2359
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&oi->ip_alloc_sem/1){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3209 [inline]
check_prevs_add kernel/locking/lockdep.c:3328 [inline]
validate_chain kernel/locking/lockdep.c:3952 [inline]
__lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
down_write_nested+0x98/0x200 kernel/locking/rwsem.c:1757
ocfs2_xattr_set_handle+0x3fc/0x820 fs/ocfs2/xattr.c:3888
ocfs2_set_acl+0x6d1/0x7b0 fs/ocfs2/acl.c:250
ocfs2_init_acl+0x1fe/0x420 fs/ocfs2/acl.c:428
ocfs2_mknod+0x1383/0x2190 fs/ocfs2/namei.c:413
ocfs2_mkdir+0x180/0x430 fs/ocfs2/namei.c:661
vfs_mkdir+0x40e/0x630 fs/namei.c:5452
filename_mkdirat+0x285/0x510 fs/namei.c:5485
__do_sys_mkdirat fs/namei.c:5506 [inline]
__se_sys_mkdirat+0x35/0x150 fs/namei.c:5503
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
&oi->ip_alloc_sem/1 --> sb_internal#4 --> &journal->j_trans_barrier
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(&journal->j_trans_barrier);
lock(sb_internal#4);
lock(&journal->j_trans_barrier);
lock(&oi->ip_alloc_sem/1);
*** DEADLOCK ***
locks held by syz.1.1388/11252: 8, last CPU#1:
#0: ffff888067e4c460 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:527
#1: ffff8880507db3a0 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline]
#1: ffff8880507db3a0 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2947 [inline]
#1: ffff8880507db3a0 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2971 [inline]
#1: ffff8880507db3a0 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5132
#2: ffff8880507e4fa0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#2: ffff8880507e4fa0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_suballoc_bits+0x170/0x4850 fs/ocfs2/suballoc.c:904
#3: ffff8880507e5da0 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#3: ffff8880507e5da0 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_suballoc_bits+0x170/0x4850 fs/ocfs2/suballoc.c:904
#4: ffff8880507e33a0 (&ocfs2_sysfile_lock_key[LOCAL_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#4: ffff8880507e33a0 (&ocfs2_sysfile_lock_key[LOCAL_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_local_alloc_bits+0x11f/0x2680 fs/ocfs2/localalloc.c:636
#5: ffff888067e4c650 (sb_internal#4){.+.+}-{0:0}, at: ocfs2_mknod+0xf07/0x2190 fs/ocfs2/namei.c:364
#6: ffff888036ee0ce0 (&journal->j_trans_barrier){.+.+}-{4:4}, at: ocfs2_start_trans+0x3a9/0x6f0 fs/ocfs2/journal.c:370
#7: ffff88802ecae950 (jbd2_handle#2){.+.+}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444
stack backtrace:
CPU: 1 UID: 0 PID: 11252 Comm: syz.1.1388 Tainted: G Y syzkaller #0 PREEMPT(full)
Tainted: [Y]=FORCED_BIND
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087
check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219
check_prev_add kernel/locking/lockdep.c:3209 [inline]
check_prevs_add kernel/locking/lockdep.c:3328 [inline]
validate_chain kernel/locking/lockdep.c:3952 [inline]
__lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
down_write_nested+0x98/0x200 kernel/locking/rwsem.c:1757
ocfs2_xattr_set_handle+0x3fc/0x820 fs/ocfs2/xattr.c:3888
ocfs2_set_acl+0x6d1/0x7b0 fs/ocfs2/acl.c:250
ocfs2_init_acl+0x1fe/0x420 fs/ocfs2/acl.c:428
ocfs2_mknod+0x1383/0x2190 fs/ocfs2/namei.c:413
ocfs2_mkdir+0x180/0x430 fs/ocfs2/namei.c:661
vfs_mkdir+0x40e/0x630 fs/namei.c:5452
filename_mkdirat+0x285/0x510 fs/namei.c:5485
__do_sys_mkdirat fs/namei.c:5506 [inline]
__se_sys_mkdirat+0x35/0x150 fs/namei.c:5503
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbdd239e1d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbdd3317028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fbdd2626090 RCX: 00007fbdd239e1d9
RDX: 00000000000001ff RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fbdd2435888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbdd2626128 R14: 00007fbdd2626090 R15: 00007ffdaf0dd208
</TASK>
* Struck through repros no longer work on HEAD.