syzbot

loop1: detected capacity change from 0 to 64
======================================================
WARNING: possible circular locking dependency detected
6.1.84-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.1/8879 is trying to acquire lock:
ffff0000dd639478 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397

but task is already holding lock:
ffff0000dacc80b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8

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+0x190/0x21a0 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
       hfs_find_init+0x148/0x1c8
       hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
       hfs_extend_file+0x270/0x1130 fs/hfs/extent.c:401
       hfs_bmap_reserve+0xd0/0x3b4 fs/hfs/btree.c:234
       hfs_cat_create+0x1bc/0x844 fs/hfs/catalog.c:104
       hfs_create+0x70/0xe4 fs/hfs/dir.c:202
       lookup_open fs/namei.c:3484 [inline]
       open_last_lookups fs/namei.c:3552 [inline]
       path_openat+0xeac/0x2548 fs/namei.c:3782
       do_filp_open+0x1bc/0x3cc fs/namei.c:3812
       do_sys_openat2+0x128/0x3d8 fs/open.c:1318
       do_sys_open fs/open.c:1334 [inline]
       __do_sys_openat fs/open.c:1350 [inline]
       __se_sys_openat fs/open.c:1345 [inline]
       __arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

-> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x3338/0x7680 kernel/locking/lockdep.c:5049
       lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662
       __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
       hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397
       hfs_bmap_reserve+0xd0/0x3b4 fs/hfs/btree.c:234
       __hfs_ext_write_extent+0x1a0/0x468 fs/hfs/extent.c:121
       __hfs_ext_cache_extent+0x84/0x754 fs/hfs/extent.c:174
       hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
       hfs_extend_file+0x29c/0x1130 fs/hfs/extent.c:401
       hfs_get_block+0x3b8/0x9e0 fs/hfs/extent.c:353
       __block_write_begin_int+0x340/0x13b4 fs/buffer.c:1991
       __block_write_begin fs/buffer.c:2041 [inline]
       block_write_begin fs/buffer.c:2102 [inline]
       cont_write_begin+0x5c0/0x7d8 fs/buffer.c:2456
       hfs_write_begin+0x98/0xe4 fs/hfs/inode.c:58
       cont_expand_zero fs/buffer.c:2383 [inline]
       cont_write_begin+0x2ac/0x7d8 fs/buffer.c:2446
       hfs_write_begin+0x98/0xe4 fs/hfs/inode.c:58
       hfs_file_truncate+0x1a4/0xeb0 fs/hfs/extent.c:494
       hfs_inode_setattr+0x3a8/0x5c8 fs/hfs/inode.c:656
       notify_change+0xb58/0xe1c fs/attr.c:499
       do_truncate+0x1c0/0x28c fs/open.c:65
       do_sys_ftruncate+0x288/0x31c fs/open.c:193
       __do_sys_ftruncate fs/open.c:204 [inline]
       __se_sys_ftruncate fs/open.c:202 [inline]
       __arm64_sys_ftruncate+0x60/0x74 fs/open.c:202
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

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-executor.1/8879:
 #0: ffff0000dc2c6460 (sb_writers#12){.+.+}-{0:0}, at: do_sys_ftruncate+0x214/0x31c fs/open.c:190
 #1: ffff0000dd639ca8 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff0000dd639ca8 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: do_truncate+0x1ac/0x28c fs/open.c:63
 #2: ffff0000dd639af8 (&HFS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397
 #3: ffff0000dacc80b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8

stack backtrace:
CPU: 1 PID: 8879 Comm: syz-executor.1 Not tainted 6.1.84-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2048
 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x3338/0x7680 kernel/locking/lockdep.c:5049
 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662
 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397
 hfs_bmap_reserve+0xd0/0x3b4 fs/hfs/btree.c:234
 __hfs_ext_write_extent+0x1a0/0x468 fs/hfs/extent.c:121
 __hfs_ext_cache_extent+0x84/0x754 fs/hfs/extent.c:174
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x29c/0x1130 fs/hfs/extent.c:401
 hfs_get_block+0x3b8/0x9e0 fs/hfs/extent.c:353
 __block_write_begin_int+0x340/0x13b4 fs/buffer.c:1991
 __block_write_begin fs/buffer.c:2041 [inline]
 block_write_begin fs/buffer.c:2102 [inline]
 cont_write_begin+0x5c0/0x7d8 fs/buffer.c:2456
 hfs_write_begin+0x98/0xe4 fs/hfs/inode.c:58
 cont_expand_zero fs/buffer.c:2383 [inline]
 cont_write_begin+0x2ac/0x7d8 fs/buffer.c:2446
 hfs_write_begin+0x98/0xe4 fs/hfs/inode.c:58
 hfs_file_truncate+0x1a4/0xeb0 fs/hfs/extent.c:494
 hfs_inode_setattr+0x3a8/0x5c8 fs/hfs/inode.c:656
 notify_change+0xb58/0xe1c fs/attr.c:499
 do_truncate+0x1c0/0x28c fs/open.c:65
 do_sys_ftruncate+0x288/0x31c fs/open.c:193
 __do_sys_ftruncate fs/open.c:204 [inline]
 __se_sys_ftruncate fs/open.c:202 [inline]
 __arm64_sys_ftruncate+0x60/0x74 fs/open.c:202
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585