====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.0.1216/11057 is trying to acquire lock: ffff88805771c0a8 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 but task is already holding lock: ffff8880554928e0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:403 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:403 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:402 __hfs_ext_write_extent+0x200/0x620 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:180 hfs_ext_read_extent fs/hfs/extent.c:208 [inline] hfs_extend_file+0x3ad/0x1680 fs/hfs/extent.c:407 hfs_get_block+0x401/0xbf0 fs/hfs/extent.c:359 __block_write_begin_int+0x6c1/0x1930 fs/buffer.c:2032 block_write_begin fs/buffer.c:2146 [inline] cont_write_begin+0x71b/0xac0 fs/buffer.c:2508 hfs_write_begin+0x123/0x1c0 fs/hfs/inode.c:62 generic_perform_write+0x2d5/0x8e0 mm/filemap.c:4399 generic_file_write_iter+0xae/0x330 mm/filemap.c:4542 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:1036 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&tree->tree_lock#2/1){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:206 [inline] hfs_extend_file+0x367/0x1680 fs/hfs/extent.c:407 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:402 hfs_cat_create+0x23d/0x870 fs/hfs/catalog.c:104 hfs_mkdir+0x73/0xe0 fs/hfs/dir.c:226 vfs_mkdir+0x411/0x660 fs/namei.c:5428 filename_mkdirat+0x284/0x550 fs/namei.c:5461 __do_sys_mkdirat fs/namei.c:5482 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5479 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock#2/1); lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock#2/1); *** DEADLOCK *** locks held by syz.0.1216/11057: 4, last CPU#0: #0: ffff888057718478 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:531 #1: ffff8880554924c0 (&type->i_mutex_dir_key#15/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1071 [inline] #1: ffff8880554924c0 (&type->i_mutex_dir_key#15/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2924 [inline] #1: ffff8880554924c0 (&type->i_mutex_dir_key#15/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2948 [inline] #1: ffff8880554924c0 (&type->i_mutex_dir_key#15/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5108 #2: ffff888056fc80a8 (&tree->tree_lock#2){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 #3: ffff8880554928e0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:403 stack backtrace: CPU: 0 UID: 0 PID: 11057 Comm: syz.0.1216 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219 check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:206 [inline] hfs_extend_file+0x367/0x1680 fs/hfs/extent.c:407 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:402 hfs_cat_create+0x23d/0x870 fs/hfs/catalog.c:104 hfs_mkdir+0x73/0xe0 fs/hfs/dir.c:226 vfs_mkdir+0x411/0x660 fs/namei.c:5428 filename_mkdirat+0x284/0x550 fs/namei.c:5461 __do_sys_mkdirat fs/namei.c:5482 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5479 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x00007fd30599e987 Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 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:00007fd3037f3e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fd3037f3ee0 RCX: 00007fd30599e987 RDX: 00000000000001ff RSI: 0000200000000140 RDI: 00000000ffffff9c RBP: 0000200000000180 R08: 0000200000000000 R09: 0000000000000000 R10: 0000200000000180 R11: 0000000000000246 R12: 0000200000000140 R13: 00007fd3037f3ea0 R14: 0000000000000000 R15: 0000200000000a40