====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.6.4406/16176 is trying to acquire lock: ffff88803117bb78 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xa6/0xcf0 fs/hfs/extent.c:397 but task is already holding lock: ffff88807912e0b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x273/0x330 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/1){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776 hfs_find_init+0x273/0x330 fs/hfs/bfind.c:36 hfs_ext_read_extent+0x19d/0x9d0 fs/hfs/extent.c:200 hfs_extend_file+0x4ff/0xcf0 fs/hfs/extent.c:401 hfs_bmap_reserve+0x2ab/0x3a0 fs/hfs/btree.c:269 hfs_cat_create+0x348/0x980 fs/hfs/catalog.c:104 hfs_mkdir+0x6f/0xe0 fs/hfs/dir.c:232 vfs_mkdir+0x729/0xb50 fs/namei.c:5139 do_mkdirat+0x435/0x590 fs/namei.c:5173 __do_sys_mkdirat fs/namei.c:5195 [inline] __se_sys_mkdirat fs/namei.c:5193 [inline] __x64_sys_mkdirat+0x112/0x170 fs/namei.c:5193 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0xf80 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+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x17c/0x330 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776 hfs_extend_file+0xa6/0xcf0 fs/hfs/extent.c:397 hfs_bmap_reserve+0x2ab/0x3a0 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x3c4/0x510 fs/hfs/extent.c:121 hfs_ext_write_extent+0x1b7/0x200 fs/hfs/extent.c:144 hfs_write_inode+0xce/0xab0 fs/hfs/inode.c:441 write_inode fs/fs-writeback.c:1582 [inline] __writeback_single_inode+0xde2/0x13c0 fs/fs-writeback.c:1802 writeback_single_inode+0x4d3/0xf30 fs/fs-writeback.c:1858 write_inode_now+0x174/0x1f0 fs/fs-writeback.c:2937 hfs_file_fsync+0xa7/0x190 fs/hfs/inode.c:688 vfs_fsync_range+0x142/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2618 [inline] generic_file_write_iter+0x30a/0x3d0 mm/filemap.c:4461 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6ac/0x1070 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+0xc9/0xf80 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/1); lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock/1); lock(&HFS_I(tree->inode)->extents_lock); *** DEADLOCK *** 4 locks held by syz.6.4406/16176: #0: ffff888078a06d38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1255 #1: ffff888021b0a420 (sb_writers#12){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #2: ffff88803117c3a0 (&sb->s_type->i_mutex_key#42){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #2: ffff88803117c3a0 (&sb->s_type->i_mutex_key#42){+.+.}-{4:4}, at: hfs_file_fsync+0x9d/0x190 fs/hfs/inode.c:685 #3: ffff88807912e0b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x273/0x330 fs/hfs/bfind.c:36 stack backtrace: CPU: 1 UID: 0 PID: 16176 Comm: syz.6.4406 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043 check_noncircular+0x146/0x160 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+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x17c/0x330 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776 hfs_extend_file+0xa6/0xcf0 fs/hfs/extent.c:397 hfs_bmap_reserve+0x2ab/0x3a0 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x3c4/0x510 fs/hfs/extent.c:121 hfs_ext_write_extent+0x1b7/0x200 fs/hfs/extent.c:144 hfs_write_inode+0xce/0xab0 fs/hfs/inode.c:441 write_inode fs/fs-writeback.c:1582 [inline] __writeback_single_inode+0xde2/0x13c0 fs/fs-writeback.c:1802 writeback_single_inode+0x4d3/0xf30 fs/fs-writeback.c:1858 write_inode_now+0x174/0x1f0 fs/fs-writeback.c:2937 hfs_file_fsync+0xa7/0x190 fs/hfs/inode.c:688 vfs_fsync_range+0x142/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2618 [inline] generic_file_write_iter+0x30a/0x3d0 mm/filemap.c:4461 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6ac/0x1070 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+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f172199aeb9 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:00007f1722796028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f1721c15fa0 RCX: 00007f172199aeb9 RDX: 0000000000001006 RSI: 0000200000001980 RDI: 0000000000000004 RBP: 00007f1721a08c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1721c16038 R14: 00007f1721c15fa0 R15: 00007ffcb3a8e278