====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.6.1360/10682 is trying to acquire lock: ffff8880776fbdc8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1cd/0x1a50 fs/hfsplus/extents.c:455 but task is already holding lock: ffff88801eb360b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&tree->tree_lock#2/1){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 hfsplus_ext_read_extent fs/hfsplus/extents.c:216 [inline] hfsplus_get_block+0x91c/0x15a0 fs/hfsplus/extents.c:268 __block_write_begin_int+0x55d/0x1a80 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin+0x96/0x1e0 fs/buffer.c:2102 cont_write_begin+0x5ea/0x800 fs/buffer.c:2456 hfsplus_write_begin+0x87/0xd0 fs/hfsplus/inode.c:52 cont_expand_zero fs/buffer.c:2383 [inline] cont_write_begin+0x2ad/0x800 fs/buffer.c:2446 hfsplus_write_begin+0x87/0xd0 fs/hfsplus/inode.c:52 generic_perform_write+0x2fa/0x5c0 mm/filemap.c:3862 __generic_file_write_iter+0x148/0x2a0 mm/filemap.c:3960 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:3989 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x4b1/0xa30 fs/read_write.c:584 ksys_pwrite64 fs/read_write.c:699 [inline] __do_sys_pwrite64 fs/read_write.c:709 [inline] __se_sys_pwrite64 fs/read_write.c:706 [inline] __x64_sys_pwrite64+0x197/0x220 fs/read_write.c:706 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 hfsplus_file_extend+0x1cd/0x1a50 fs/hfsplus/extents.c:455 hfsplus_bmap_reserve+0x11e/0x4f0 fs/hfsplus/btree.c:358 __hfsplus_ext_write_extent+0x28d/0x5b0 fs/hfsplus/extents.c:104 __hfsplus_ext_cache_extent+0x89/0xe20 fs/hfsplus/extents.c:186 hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline] hfsplus_file_extend+0x4be/0x1a50 fs/hfsplus/extents.c:459 hfsplus_get_block+0x430/0x15a0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x55d/0x1a80 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin+0x96/0x1e0 fs/buffer.c:2102 cont_write_begin+0x5ea/0x800 fs/buffer.c:2456 hfsplus_write_begin+0x87/0xd0 fs/hfsplus/inode.c:52 cont_expand_zero fs/buffer.c:2383 [inline] cont_write_begin+0x2ad/0x800 fs/buffer.c:2446 hfsplus_write_begin+0x87/0xd0 fs/hfsplus/inode.c:52 generic_cont_expand_simple+0x13d/0x200 fs/buffer.c:2347 hfsplus_setattr+0x165/0x280 fs/hfsplus/inode.c:283 notify_change+0xc74/0xf40 fs/attr.c:499 do_truncate+0x1ac/0x240 fs/open.c:65 do_sys_ftruncate+0x312/0x3c0 fs/open.c:193 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&tree->tree_lock#2/1); lock(&HFSPLUS_I(inode)->extents_lock); lock(&tree->tree_lock#2/1); lock(&HFSPLUS_I(inode)->extents_lock); *** DEADLOCK *** 4 locks held by syz.6.1360/10682: #0: ffff88807619c460 (sb_writers#23){.+.+}-{0:0}, at: do_sys_ftruncate+0x27b/0x3c0 fs/open.c:190 #1: ffff8880776fd400 (&sb->s_type->i_mutex_key#27){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff8880776fd400 (&sb->s_type->i_mutex_key#27){+.+.}-{3:3}, at: do_truncate+0x198/0x240 fs/open.c:63 #2: ffff8880776fd208 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1cd/0x1a50 fs/hfsplus/extents.c:455 #3: ffff88801eb360b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 stack backtrace: CPU: 1 PID: 10682 Comm: syz.6.1360 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 hfsplus_file_extend+0x1cd/0x1a50 fs/hfsplus/extents.c:455 hfsplus_bmap_reserve+0x11e/0x4f0 fs/hfsplus/btree.c:358 __hfsplus_ext_write_extent+0x28d/0x5b0 fs/hfsplus/extents.c:104 __hfsplus_ext_cache_extent+0x89/0xe20 fs/hfsplus/extents.c:186 hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline] hfsplus_file_extend+0x4be/0x1a50 fs/hfsplus/extents.c:459 hfsplus_get_block+0x430/0x15a0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x55d/0x1a80 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin+0x96/0x1e0 fs/buffer.c:2102 cont_write_begin+0x5ea/0x800 fs/buffer.c:2456 hfsplus_write_begin+0x87/0xd0 fs/hfsplus/inode.c:52 cont_expand_zero fs/buffer.c:2383 [inline] cont_write_begin+0x2ad/0x800 fs/buffer.c:2446 hfsplus_write_begin+0x87/0xd0 fs/hfsplus/inode.c:52 generic_cont_expand_simple+0x13d/0x200 fs/buffer.c:2347 hfsplus_setattr+0x165/0x280 fs/hfsplus/inode.c:283 notify_change+0xc74/0xf40 fs/attr.c:499 do_truncate+0x1ac/0x240 fs/open.c:65 do_sys_ftruncate+0x312/0x3c0 fs/open.c:193 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa392d9c819 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:00007fa393c3e028 EFLAGS: 00000246 ORIG_RAX: 000000000000004d RAX: ffffffffffffffda RBX: 00007fa393015fa0 RCX: 00007fa392d9c819 RDX: 0000000000000000 RSI: 0000000002000009 RDI: 0000000000000004 RBP: 00007fa392e32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa393016038 R14: 00007fa393015fa0 R15: 00007ffcce08ec98