[syzbot] [ocfs2?] possible deadlock in ocfs2_remove_refcount_tree

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 174914ea5513 Merge tag 'v7.1-rc6-smb3-client-fixes' of git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15dbad2e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b4166e8ea5fbf7e3
dashboard link: https://syzkaller.appspot.com/bug?extid=ad7eca1cdf5d9c9db672
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-174914ea.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/343eb2c4ac93/vmlinux-174914ea.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b9e6c020ebad/bzImage-174914ea.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ad7eca...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.0/5329 is trying to acquire lock:
ffff888047a9c1a0 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
ffff888047a9c1a0 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_remove_refcount_tree+0x58d/0xe50 fs/ocfs2/refcounttree.c:803

but task is already holding lock:
ffff888012277090 (&new->rf_sem){+.+.}-{4:4}, at: __ocfs2_lock_refcount_tree fs/ocfs2/refcounttree.c:428 [inline]
ffff888012277090 (&new->rf_sem){+.+.}-{4:4}, at: ocfs2_lock_refcount_tree+0x1b7/0xa40 fs/ocfs2/refcounttree.c:463

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&new->rf_sem){+.+.}-{4:4}:
down_write+0x96/0x200 kernel/locking/rwsem.c:1625
__ocfs2_lock_refcount_tree fs/ocfs2/refcounttree.c:428 [inline]
ocfs2_lock_refcount_tree+0x1b7/0xa40 fs/ocfs2/refcounttree.c:463
ocfs2_remove_refcount_tree+0x245/0xe50 fs/ocfs2/refcounttree.c:775
ocfs2_wipe_inode fs/ocfs2/inode.c:890 [inline]
ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
ocfs2_evict_inode+0x142b/0x43b0 fs/ocfs2/inode.c:1299
evict+0x61e/0xb10 fs/inode.c:841
ocfs2_dentry_iput+0x24d/0x390 fs/ocfs2/dcache.c:407
__dentry_kill+0x1a2/0x690 fs/dcache.c:718
finish_dput+0xc9/0x480 fs/dcache.c:927
__fput+0x691/0xa60 fs/file_table.c:518
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0x193/0x680 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}:
down_write+0x96/0x200 kernel/locking/rwsem.c:1625
inode_lock include/linux/fs.h:1029 [inline]
ocfs2_del_inode_from_orphan+0x12e/0x7a0 fs/ocfs2/namei.c:2728
ocfs2_dio_end_io_write fs/ocfs2/aops.c:2379 [inline]
ocfs2_dio_end_io+0xf9c/0x1370 fs/ocfs2/aops.c:2418
dio_complete+0x25b/0x790 fs/direct-io.c:281
__blockdev_direct_IO+0x2e5d/0x34e0 fs/direct-io.c:1303
ocfs2_direct_IO+0x251/0x2c0 fs/ocfs2/aops.c:2455
generic_file_direct_write+0x1db/0x3e0 mm/filemap.c:4259
__generic_file_write_iter+0x11d/0x230 mm/filemap.c:4428
ocfs2_file_write_iter+0x1663/0x1e70 fs/ocfs2/file.c:2476
iter_file_splice_write+0x9a1/0x10f0 fs/splice.c:736
do_splice_from fs/splice.c:936 [inline]
direct_splice_actor+0x101/0x160 fs/splice.c:1159
splice_direct_to_actor+0x53a/0xc70 fs/splice.c:1103
do_splice_direct_actor fs/splice.c:1202 [inline]
do_splice_direct+0x195/0x290 fs/splice.c:1228
do_sendfile+0x535/0x7d0 fs/read_write.c:1372
__do_sys_sendfile64 fs/read_write.c:1433 [inline]
__se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1419
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&ocfs2_sysfile_lock_key[EXTENT_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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
down_write+0x96/0x200 kernel/locking/rwsem.c:1625
inode_lock include/linux/fs.h:1029 [inline]
ocfs2_remove_refcount_tree+0x58d/0xe50 fs/ocfs2/refcounttree.c:803
ocfs2_wipe_inode fs/ocfs2/inode.c:890 [inline]
ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
ocfs2_evict_inode+0x142b/0x43b0 fs/ocfs2/inode.c:1299
evict+0x61e/0xb10 fs/inode.c:841
ocfs2_dentry_iput+0x24d/0x390 fs/ocfs2/dcache.c:407
__dentry_kill+0x1a2/0x690 fs/dcache.c:718
finish_dput+0xc9/0x480 fs/dcache.c:927
__fput+0x691/0xa60 fs/file_table.c:518
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0x193/0x680 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE] --> &ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE] --> &new->rf_sem

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&new->rf_sem);
lock(&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]);
lock(&new->rf_sem);
lock(&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]);

*** DEADLOCK ***

3 locks held by syz.0.0/5329:
#0: ffff888012048bc0 (&osb->nfs_sync_rwlock){.+.+}-{4:4}, at: ocfs2_nfs_sync_lock+0x106/0x270 fs/ocfs2/dlmglue.c:2875
#1: ffff888047a9cfa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
#1: ffff888047a9cfa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_wipe_inode fs/ocfs2/inode.c:854 [inline]
#1: ffff888047a9cfa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
#1: ffff888047a9cfa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_evict_inode+0xe97/0x43b0 fs/ocfs2/inode.c:1299
#2: ffff888012277090 (&new->rf_sem){+.+.}-{4:4}, at: __ocfs2_lock_refcount_tree fs/ocfs2/refcounttree.c:428 [inline]
#2: ffff888012277090 (&new->rf_sem){+.+.}-{4:4}, at: ocfs2_lock_refcount_tree+0x1b7/0xa40 fs/ocfs2/refcounttree.c:463

stack backtrace:
CPU: 0 UID: 0 PID: 5329 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), 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+0x2e1/0x300 kernel/locking/lockdep.c:2043
check_noncircular+0x12e/0x150 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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
down_write+0x96/0x200 kernel/locking/rwsem.c:1625
inode_lock include/linux/fs.h:1029 [inline]
ocfs2_remove_refcount_tree+0x58d/0xe50 fs/ocfs2/refcounttree.c:803
ocfs2_wipe_inode fs/ocfs2/inode.c:890 [inline]
ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
ocfs2_evict_inode+0x142b/0x43b0 fs/ocfs2/inode.c:1299
evict+0x61e/0xb10 fs/inode.c:841
ocfs2_dentry_iput+0x24d/0x390 fs/ocfs2/dcache.c:407
__dentry_kill+0x1a2/0x690 fs/dcache.c:718
finish_dput+0xc9/0x480 fs/dcache.c:927
__fput+0x691/0xa60 fs/file_table.c:518
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0x193/0x680 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1074f9ce59
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:00007ffcfa6825f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffcfa6826e0 RCX: 00007f1074f9ce59
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000012125 R08: 0000000000000001 R09: 0000000000000000
R10: 00007f1074dff030 R11: 0000000000000246 R12: 00007ffcfa682720
R13: 00007f1075215fac R14: 0000000000012813 R15: 00007f1075215fa0
</TASK>


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