loop2: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.2.211/7047 is trying to acquire lock: ffff88801eaad208 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x211/0x19e0 fs/hfsplus/extents.c:455 but task is already holding lock: ffff88806bbc20b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x154/0x1d0 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/1){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747 hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28 hfsplus_ext_read_extent fs/hfsplus/extents.c:216 [inline] hfsplus_file_extend+0x45e/0x19e0 fs/hfsplus/extents.c:459 hfsplus_get_block+0x434/0x15a0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x57f/0x1af0 fs/buffer.c:2124 __block_write_begin fs/buffer.c:2173 [inline] block_write_begin+0x9a/0x1e0 fs/buffer.c:2234 cont_write_begin+0x5ee/0x810 fs/buffer.c:2591 hfsplus_write_begin+0x8b/0xd0 fs/hfsplus/inode.c:52 cont_expand_zero fs/buffer.c:2518 [inline] cont_write_begin+0x2b1/0x810 fs/buffer.c:2581 hfsplus_write_begin+0x8b/0xd0 fs/hfsplus/inode.c:52 generic_cont_expand_simple+0x141/0x200 fs/buffer.c:2482 hfsplus_setattr+0x169/0x280 fs/hfsplus/inode.c:283 notify_change+0xb0d/0xe10 fs/attr.c:499 do_truncate+0x1b0/0x240 fs/open.c:66 do_sys_ftruncate+0x325/0x3d0 fs/open.c:194 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 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:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747 hfsplus_file_extend+0x211/0x19e0 fs/hfsplus/extents.c:455 hfsplus_bmap_reserve+0x122/0x500 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+0x4a5/0x19e0 fs/hfsplus/extents.c:459 hfsplus_get_block+0x434/0x15a0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x57f/0x1af0 fs/buffer.c:2124 __block_write_begin fs/buffer.c:2173 [inline] block_write_begin+0x9a/0x1e0 fs/buffer.c:2234 cont_write_begin+0x5ee/0x810 fs/buffer.c:2591 hfsplus_write_begin+0x8b/0xd0 fs/hfsplus/inode.c:52 generic_perform_write+0x2fe/0x5c0 mm/filemap.c:4031 generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4152 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x46c/0x990 fs/read_write.c:584 ksys_write+0x150/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 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/1); lock(&HFSPLUS_I(inode)->extents_lock); lock(&tree->tree_lock/1); lock(&HFSPLUS_I(inode)->extents_lock); *** DEADLOCK *** 5 locks held by syz.2.211/7047: #0: ffff88803063d9c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040 #1: ffff88805cc04418 (sb_writers#20){.+.+}-{0:0}, at: vfs_write+0x21b/0x990 fs/read_write.c:580 #2: ffff88807fecb910 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #2: ffff88807fecb910 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: generic_file_write_iter+0x83/0x2e0 mm/filemap.c:4149 #3: ffff88807fecb708 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x211/0x19e0 fs/hfsplus/extents.c:455 #4: ffff88806bbc20b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28 stack backtrace: CPU: 0 PID: 7047 Comm: syz.2.211 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747 hfsplus_file_extend+0x211/0x19e0 fs/hfsplus/extents.c:455 hfsplus_bmap_reserve+0x122/0x500 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+0x4a5/0x19e0 fs/hfsplus/extents.c:459 hfsplus_get_block+0x434/0x15a0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x57f/0x1af0 fs/buffer.c:2124 __block_write_begin fs/buffer.c:2173 [inline] block_write_begin+0x9a/0x1e0 fs/buffer.c:2234 cont_write_begin+0x5ee/0x810 fs/buffer.c:2591 hfsplus_write_begin+0x8b/0xd0 fs/hfsplus/inode.c:52 generic_perform_write+0x2fe/0x5c0 mm/filemap.c:4031 generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4152 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x46c/0x990 fs/read_write.c:584 ksys_write+0x150/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1742f9bf79 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:00007f1743d9a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f1743215fa0 RCX: 00007f1742f9bf79 RDX: 000000000208e24b RSI: 0000200000000040 RDI: 0000000000000004 RBP: 00007f17430327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1743216038 R14: 00007f1743215fa0 R15: 00007ffc6cd5f838