syzbot

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz-executor/4284 is trying to acquire lock:
ffff88807cf240b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28

but task is already holding lock:
ffff88807b4f0108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x2a0/0xb40 fs/hfsplus/extents.c:574

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}:
       __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       hfsplus_file_extend+0x1b3/0x1950 fs/hfsplus/extents.c:455
       hfsplus_bmap_reserve+0x11e/0x4f0 fs/hfsplus/btree.c:357
       __hfsplus_ext_write_extent+0x28d/0x5b0 fs/hfsplus/extents.c:104
       __hfsplus_ext_cache_extent+0x89/0xe20 fs/hfsplus/extents.c:186
       hfsplus_file_truncate+0x467/0xb40 fs/hfsplus/extents.c:597
       hfsplus_setattr+0x1c0/0x280 fs/hfsplus/inode.c:267
       notify_change+0xbcd/0xee0 fs/attr.c:505
       do_truncate+0x197/0x220 fs/open.c:65
       vfs_truncate+0x262/0x2f0 fs/open.c:111
       do_sys_truncate+0xdc/0x190 fs/open.c:134
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&tree->tree_lock/1){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
       lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
       hfsplus_file_truncate+0x38c/0xb40 fs/hfsplus/extents.c:580
       hfsplus_delete_inode+0x17c/0x230 fs/hfsplus/inode.c:-1
       hfsplus_unlink+0x4c0/0x760 fs/hfsplus/dir.c:405
       vfs_unlink+0x385/0x600 fs/namei.c:4288
       do_unlinkat+0x382/0x6f0 fs/namei.c:4356
       __do_sys_unlink fs/namei.c:4404 [inline]
       __se_sys_unlink fs/namei.c:4402 [inline]
       __x64_sys_unlink+0x45/0x50 fs/namei.c:4402
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&HFSPLUS_I(inode)->extents_lock);
                               lock(&tree->tree_lock/1);
                               lock(&HFSPLUS_I(inode)->extents_lock);
  lock(&tree->tree_lock/1);

 *** DEADLOCK ***

5 locks held by syz-executor/4284:
 #0: ffff88807cf22460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff88807d899e00 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff88807d899e00 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: do_unlinkat+0x1b9/0x6f0 fs/namei.c:4339
 #2: ffff88807b4f0300 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #2: ffff88807b4f0300 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: vfs_unlink+0xee/0x600 fs/namei.c:4277
 #3: ffff8880721d2998 (&sbi->vh_mutex){+.+.}-{3:3}, at: hfsplus_unlink+0x15a/0x760 fs/hfsplus/dir.c:370
 #4: ffff88807b4f0108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x2a0/0xb40 fs/hfsplus/extents.c:574

stack backtrace:
CPU: 0 PID: 4284 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
 hfsplus_file_truncate+0x38c/0xb40 fs/hfsplus/extents.c:580
 hfsplus_delete_inode+0x17c/0x230 fs/hfsplus/inode.c:-1
 hfsplus_unlink+0x4c0/0x760 fs/hfsplus/dir.c:405
 vfs_unlink+0x385/0x600 fs/namei.c:4288
 do_unlinkat+0x382/0x6f0 fs/namei.c:4356
 __do_sys_unlink fs/namei.c:4404 [inline]
 __se_sys_unlink fs/namei.c:4402 [inline]
 __x64_sys_unlink+0x45/0x50 fs/namei.c:4402
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f54cbd02577
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 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:00007fff0c79fb48 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f54cbd02577
RDX: 00007fff0c79fb70 RSI: 00007fff0c79fc00 RDI: 00007fff0c79fc00
RBP: 00007fff0c79fc00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007fff0c7a0cf0
R13: 00007f54cbd85d7d R14: 0000000000010f86 R15: 00007fff0c7a1dc0
 </TASK>