loop7: detected capacity change from 0 to 64 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.7.6737/10738 is trying to acquire lock: ffff88806c2a34f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xa1/0xb10 fs/hfs/extent.c:397 but task is already holding lock: ffff88803cd540b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x1c3/0x240 fs/hfs/bfind.c:36 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&tree->tree_lock#2/1){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x193/0x1060 kernel/locking/mutex.c:760 hfs_find_init+0x1c3/0x240 fs/hfs/bfind.c:36 hfs_ext_read_extent+0x19b/0x9e0 fs/hfs/extent.c:200 hfs_extend_file+0x4e2/0xb10 fs/hfs/extent.c:401 hfs_bmap_reserve+0x2a2/0x390 fs/hfs/btree.c:269 hfs_cat_create+0x229/0x820 fs/hfs/catalog.c:104 hfs_mkdir+0x6f/0xe0 fs/hfs/dir.c:232 vfs_mkdir+0x593/0x8c0 fs/namei.c:4366 do_mkdirat+0x304/0x3e0 fs/namei.c:4399 __do_sys_mkdirat fs/namei.c:4416 [inline] __se_sys_mkdirat fs/namei.c:4414 [inline] __x64_sys_mkdirat+0x83/0xb0 fs/namei.c:4414 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{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+0x12a6/0x1ce0 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x193/0x1060 kernel/locking/mutex.c:760 hfs_extend_file+0xa1/0xb10 fs/hfs/extent.c:397 hfs_bmap_reserve+0x2a2/0x390 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x3cf/0x520 fs/hfs/extent.c:121 __hfs_ext_cache_extent fs/hfs/extent.c:174 [inline] hfs_ext_read_extent+0x807/0x9e0 fs/hfs/extent.c:202 hfs_extend_file+0x4e2/0xb10 fs/hfs/extent.c:401 hfs_get_block+0x17f/0x830 fs/hfs/extent.c:353 __block_write_begin_int+0x4f4/0x16d0 fs/buffer.c:2145 block_write_begin+0x9a/0x1d0 fs/buffer.c:2256 cont_write_begin+0x61b/0x950 fs/buffer.c:2594 hfs_write_begin+0x64/0x120 fs/hfs/inode.c:52 generic_perform_write+0x3c5/0x900 mm/filemap.c:4175 __generic_file_write_iter+0x1f7/0x240 mm/filemap.c:4292 generic_file_write_iter+0xe1/0x3c0 mm/filemap.c:4318 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x7d3/0x11d0 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&tree->tree_lock#2/1); lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock#2/1); lock(&HFS_I(tree->inode)->extents_lock); *** DEADLOCK *** 5 locks held by syz.7.6737/10738: #0: ffff8880301780f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1232 #1: ffff88803cd52428 (sb_writers#30){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #2: ffff88806c2a3d20 (&sb->s_type->i_mutex_key#38){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #2: ffff88806c2a3d20 (&sb->s_type->i_mutex_key#38){+.+.}-{4:4}, at: generic_file_write_iter+0x8c/0x3c0 mm/filemap.c:4315 #3: ffff88806c2a3b78 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xa1/0xb10 fs/hfs/extent.c:397 #4: ffff88803cd540b0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x1c3/0x240 fs/hfs/bfind.c:36 stack backtrace: CPU: 1 UID: 0 PID: 10738 Comm: syz.7.6737 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2043 check_noncircular+0x14c/0x170 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+0x12a6/0x1ce0 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x193/0x1060 kernel/locking/mutex.c:760 hfs_extend_file+0xa1/0xb10 fs/hfs/extent.c:397 hfs_bmap_reserve+0x2a2/0x390 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x3cf/0x520 fs/hfs/extent.c:121 __hfs_ext_cache_extent fs/hfs/extent.c:174 [inline] hfs_ext_read_extent+0x807/0x9e0 fs/hfs/extent.c:202 hfs_extend_file+0x4e2/0xb10 fs/hfs/extent.c:401 hfs_get_block+0x17f/0x830 fs/hfs/extent.c:353 __block_write_begin_int+0x4f4/0x16d0 fs/buffer.c:2145 block_write_begin+0x9a/0x1d0 fs/buffer.c:2256 cont_write_begin+0x61b/0x950 fs/buffer.c:2594 hfs_write_begin+0x64/0x120 fs/hfs/inode.c:52 generic_perform_write+0x3c5/0x900 mm/filemap.c:4175 __generic_file_write_iter+0x1f7/0x240 mm/filemap.c:4292 generic_file_write_iter+0xe1/0x3c0 mm/filemap.c:4318 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x7d3/0x11d0 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa501b8ebe9 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:00007fa502ad2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fa501db5fa0 RCX: 00007fa501b8ebe9 RDX: 0000000000001001 RSI: 0000200000000940 RDI: 0000000000000004 RBP: 00007fa501c11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa501db6038 R14: 00007fa501db5fa0 R15: 00007fffbe997b38