loop6: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.6.544/8399 is trying to acquire lock: ffff888030410108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1fd/0x1990 fs/hfsplus/extents.c:455 but task is already holding lock: ffff88807bc640b0 (&tree->tree_lock#2/1){+.+.}-{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#2/1){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747 hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28 hfsplus_ext_write_extent_locked fs/hfsplus/extents.c:136 [inline] hfsplus_ext_write_extent+0x14c/0x200 fs/hfsplus/extents.c:150 hfsplus_write_inode+0x22/0x5e0 fs/hfsplus/super.c:167 write_inode fs/fs-writeback.c:1483 [inline] __writeback_single_inode+0x705/0xee0 fs/fs-writeback.c:1700 writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926 wb_writeback+0x450/0xba0 fs/fs-writeback.c:2105 wb_do_writeback fs/fs-writeback.c:2252 [inline] wb_workfn+0x3ff/0xe20 fs/fs-writeback.c:2292 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 -> #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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747 hfsplus_file_extend+0x1fd/0x1990 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+0x445/0x1990 fs/hfsplus/extents.c:459 hfsplus_get_block+0x412/0x1530 fs/hfsplus/extents.c:245 __block_write_begin_int+0x566/0x1ad0 fs/buffer.c:2124 __block_write_begin fs/buffer.c:2173 [inline] block_write_begin+0x9a/0x1e0 fs/buffer.c:2234 cont_write_begin+0x5c8/0x7e0 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+0x2ad/0x7e0 fs/buffer.c:2581 hfsplus_write_begin+0x8b/0xd0 fs/hfsplus/inode.c:52 generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4031 generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4152 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x79a/0xc70 fs/read_write.c:860 vfs_writev fs/read_write.c:933 [inline] do_pwritev+0x205/0x340 fs/read_write.c:1030 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 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.6.544/8399: #0: ffff888029d62418 (sb_writers#36){.+.+}-{0:0}, at: vfs_writev fs/read_write.c:932 [inline] #0: ffff888029d62418 (sb_writers#36){.+.+}-{0:0}, at: do_pwritev+0x1f3/0x340 fs/read_write.c:1030 #1: ffff888030412b90 (&sb->s_type->i_mutex_key#35){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff888030412b90 (&sb->s_type->i_mutex_key#35){+.+.}-{3:3}, at: generic_file_write_iter+0x83/0x2e0 mm/filemap.c:4149 #2: ffff888030412988 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1fd/0x1990 fs/hfsplus/extents.c:455 #3: ffff88807bc640b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28 stack backtrace: CPU: 0 PID: 8399 Comm: syz.6.544 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_noncircular+0x2bd/0x3c0 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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747 hfsplus_file_extend+0x1fd/0x1990 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+0x445/0x1990 fs/hfsplus/extents.c:459 hfsplus_get_block+0x412/0x1530 fs/hfsplus/extents.c:245 __block_write_begin_int+0x566/0x1ad0 fs/buffer.c:2124 __block_write_begin fs/buffer.c:2173 [inline] block_write_begin+0x9a/0x1e0 fs/buffer.c:2234 cont_write_begin+0x5c8/0x7e0 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+0x2ad/0x7e0 fs/buffer.c:2581 hfsplus_write_begin+0x8b/0xd0 fs/hfsplus/inode.c:52 generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4031 generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4152 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x79a/0xc70 fs/read_write.c:860 vfs_writev fs/read_write.c:933 [inline] do_pwritev+0x205/0x340 fs/read_write.c:1030 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3c3d98f749 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:00007f3c3e883038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148 RAX: ffffffffffffffda RBX: 00007f3c3dbe5fa0 RCX: 00007f3c3d98f749 RDX: 0000000000000001 RSI: 00002000000015c0 RDI: 0000000000000009 RBP: 00007f3c3da13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000fffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3c3dbe6038 R14: 00007f3c3dbe5fa0 R15: 00007ffef5973118