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Message-ID: <687be24a.a70a0220.693ce.0092.GAE@google.com>
Date: Sat, 19 Jul 2025 11:22:02 -0700
From: syzbot <syzbot+1fed2de07d8e11a3ec1b@...kaller.appspotmail.com>
To: linux-kernel@...r.kernel.org, penguin-kernel@...ove.sakura.ne.jp,
syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [ocfs2?] possible deadlock in ocfs2_try_remove_refcount_tree
Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
possible deadlock in ocfs2_truncate_file
option from the mount to silence this warning.
=======================================================
ocfs2: Mounting device (7,0) on (node local, slot 0) with writeback data mode.
======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc6-syzkaller-00253-g4871b7cb27f4-dirty #0 Not tainted
------------------------------------------------------
syz.0.16/6592 is trying to acquire lock:
ffff88807a9fc618 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_orphan_for_truncate fs/ocfs2/file.c:396 [inline]
ffff88807a9fc618 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_truncate_file+0x648/0x1410 fs/ocfs2/file.c:500
but task is already holding lock:
ffff88807da38660 (&oi->ip_alloc_sem){++++}-{4:4}, at: ocfs2_down_write fs/ocfs2/inode.h:74 [inline]
ffff88807da38660 (&oi->ip_alloc_sem){++++}-{4:4}, at: ocfs2_truncate_file+0x36a/0x1410 fs/ocfs2/file.c:471
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&oi->ip_alloc_sem){++++}-{4:4}:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
down_write+0x96/0x1f0 kernel/locking/rwsem.c:1577
ocfs2_down_write fs/ocfs2/inode.h:74 [inline]
ocfs2_xattr_set_handle+0x3af/0x7a0 fs/ocfs2/xattr.c:3503
ocfs2_init_security_set+0xbd/0xe0 fs/ocfs2/xattr.c:7309
ocfs2_mknod+0x137f/0x2050 fs/ocfs2/namei.c:419
ocfs2_create+0x1a5/0x440 fs/ocfs2/namei.c:673
lookup_open fs/namei.c:3717 [inline]
open_last_lookups fs/namei.c:3816 [inline]
path_openat+0x14f1/0x3830 fs/namei.c:4052
do_filp_open+0x1fa/0x410 fs/namei.c:4082
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_open fs/open.c:1460 [inline]
__se_sys_open fs/open.c:1456 [inline]
__x64_sys_open+0x11e/0x150 fs/open.c:1456
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #3 (&oi->ip_xattr_sem){++++}-{4:4}:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
down_write+0x96/0x1f0 kernel/locking/rwsem.c:1577
ocfs2_down_write fs/ocfs2/inode.h:73 [inline]
ocfs2_xattr_set_handle+0x3a0/0x7a0 fs/ocfs2/xattr.c:3503
ocfs2_init_security_set+0xbd/0xe0 fs/ocfs2/xattr.c:7309
ocfs2_mknod+0x137f/0x2050 fs/ocfs2/namei.c:419
ocfs2_create+0x1a5/0x440 fs/ocfs2/namei.c:673
lookup_open fs/namei.c:3717 [inline]
open_last_lookups fs/namei.c:3816 [inline]
path_openat+0x14f1/0x3830 fs/namei.c:4052
do_filp_open+0x1fa/0x410 fs/namei.c:4082
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_open fs/open.c:1460 [inline]
__se_sys_open fs/open.c:1456 [inline]
__x64_sys_open+0x11e/0x150 fs/open.c:1456
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #2 (jbd2_handle){++++}-{0:0}:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
start_this_handle+0x1fa7/0x21c0 fs/jbd2/transaction.c:444
jbd2__journal_start+0x2c1/0x5b0 fs/jbd2/transaction.c:501
jbd2_journal_start+0x2a/0x40 fs/jbd2/transaction.c:540
ocfs2_start_trans+0x376/0x6d0 fs/ocfs2/journal.c:374
ocfs2_block_group_alloc fs/ocfs2/suballoc.c:685 [inline]
ocfs2_reserve_suballoc_bits+0x711/0x4640 fs/ocfs2/suballoc.c:834
ocfs2_reserve_new_metadata_blocks+0x403/0x940 fs/ocfs2/suballoc.c:984
ocfs2_mknod+0xe08/0x2050 fs/ocfs2/namei.c:347
ocfs2_create+0x1a5/0x440 fs/ocfs2/namei.c:673
lookup_open fs/namei.c:3717 [inline]
open_last_lookups fs/namei.c:3816 [inline]
path_openat+0x14f1/0x3830 fs/namei.c:4052
do_filp_open+0x1fa/0x410 fs/namei.c:4082
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_open fs/open.c:1460 [inline]
__se_sys_open fs/open.c:1456 [inline]
__x64_sys_open+0x11e/0x150 fs/open.c:1456
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (&journal->j_trans_barrier){.+.+}-{4:4}:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
down_read+0x46/0x2e0 kernel/locking/rwsem.c:1524
ocfs2_start_trans+0x36a/0x6d0 fs/ocfs2/journal.c:372
ocfs2_block_group_alloc fs/ocfs2/suballoc.c:685 [inline]
ocfs2_reserve_suballoc_bits+0x711/0x4640 fs/ocfs2/suballoc.c:834
ocfs2_reserve_new_metadata_blocks+0x403/0x940 fs/ocfs2/suballoc.c:984
ocfs2_mknod+0xe08/0x2050 fs/ocfs2/namei.c:347
ocfs2_create+0x1a5/0x440 fs/ocfs2/namei.c:673
lookup_open fs/namei.c:3717 [inline]
open_last_lookups fs/namei.c:3816 [inline]
path_openat+0x14f1/0x3830 fs/namei.c:4052
do_filp_open+0x1fa/0x410 fs/namei.c:4082
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_open fs/open.c:1460 [inline]
__se_sys_open fs/open.c:1456 [inline]
__x64_sys_open+0x11e/0x150 fs/open.c:1456
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (sb_internal#2){.+.+}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3168 [inline]
check_prevs_add kernel/locking/lockdep.c:3287 [inline]
validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
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.h:1795 [inline]
sb_start_intwrite include/linux/fs.h:1978 [inline]
ocfs2_start_trans+0x26b/0x6d0 fs/ocfs2/journal.c:370
ocfs2_orphan_for_truncate fs/ocfs2/file.c:396 [inline]
ocfs2_truncate_file+0x648/0x1410 fs/ocfs2/file.c:500
ocfs2_setattr+0x1571/0x1b60 fs/ocfs2/file.c:1212
notify_change+0xb36/0xe40 fs/attr.c:552
do_truncate+0x1a4/0x220 fs/open.c:68
handle_truncate fs/namei.c:3517 [inline]
do_open fs/namei.c:3900 [inline]
path_openat+0x306c/0x3830 fs/namei.c:4055
do_filp_open+0x1fa/0x410 fs/namei.c:4082
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_open fs/open.c:1460 [inline]
__se_sys_open fs/open.c:1456 [inline]
__x64_sys_open+0x11e/0x150 fs/open.c:1456
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
sb_internal#2 --> &oi->ip_xattr_sem --> &oi->ip_alloc_sem
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&oi->ip_alloc_sem);
lock(&oi->ip_xattr_sem);
lock(&oi->ip_alloc_sem);
rlock(sb_internal#2);
*** DEADLOCK ***
4 locks held by syz.0.16/6592:
#0: ffff88807a9fc428 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
#1: ffff88807da389c0 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:874 [inline]
#1: ffff88807da389c0 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63
#2: ffff88807da386f8 (&oi->ip_xattr_sem){++++}-{4:4}, at: ocfs2_down_write fs/ocfs2/inode.h:73 [inline]
#2: ffff88807da386f8 (&oi->ip_xattr_sem){++++}-{4:4}, at: ocfs2_truncate_file+0x359/0x1410 fs/ocfs2/file.c:471
#3: ffff88807da38660 (&oi->ip_alloc_sem){++++}-{4:4}, at: ocfs2_down_write fs/ocfs2/inode.h:74 [inline]
#3: ffff88807da38660 (&oi->ip_alloc_sem){++++}-{4:4}, at: ocfs2_truncate_file+0x36a/0x1410 fs/ocfs2/file.c:471
stack backtrace:
CPU: 1 UID: 0 PID: 6592 Comm: syz.0.16 Not tainted 6.16.0-rc6-syzkaller-00253-g4871b7cb27f4-dirty #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2046
check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2178
check_prev_add kernel/locking/lockdep.c:3168 [inline]
check_prevs_add kernel/locking/lockdep.c:3287 [inline]
validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
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.h:1795 [inline]
sb_start_intwrite include/linux/fs.h:1978 [inline]
ocfs2_start_trans+0x26b/0x6d0 fs/ocfs2/journal.c:370
ocfs2_orphan_for_truncate fs/ocfs2/file.c:396 [inline]
ocfs2_truncate_file+0x648/0x1410 fs/ocfs2/file.c:500
ocfs2_setattr+0x1571/0x1b60 fs/ocfs2/file.c:1212
notify_change+0xb36/0xe40 fs/attr.c:552
do_truncate+0x1a4/0x220 fs/open.c:68
handle_truncate fs/namei.c:3517 [inline]
do_open fs/namei.c:3900 [inline]
path_openat+0x306c/0x3830 fs/namei.c:4055
do_filp_open+0x1fa/0x410 fs/namei.c:4082
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_open fs/open.c:1460 [inline]
__se_sys_open fs/open.c:1456 [inline]
__x64_sys_open+0x11e/0x150 fs/open.c:1456
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa61778e929
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:00007fa61868b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fa6179b5fa0 RCX: 00007fa61778e929
RDX: 0000000000000020 RSI: 000000000014927e RDI: 00002000000001c0
RBP: 00007fa617810b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa6179b5fa0 R15: 00007fffb0c2bbe8
</TASK>
Tested on:
commit: 4871b7cb Merge tag 'v6.16-rc6-smb3-client-fixes' of gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1474c38c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f09d04131ef56b22
dashboard link: https://syzkaller.appspot.com/bug?extid=1fed2de07d8e11a3ec1b
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
patch: https://syzkaller.appspot.com/x/patch.diff?x=1510c38c580000
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