loop4: detected capacity change from 0 to 64
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.4.1268/15758 is trying to acquire lock:
ffff8880320366a8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x14c0 fs/hfs/extent.c:397
but task is already holding lock:
ffff888050cfe0a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x2c0 fs/hfs/bfind.c:-1
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/rtmutex_api.c:533 [inline]
mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
hfs_find_init+0x18e/0x2c0 fs/hfs/bfind.c:-1
hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
hfs_extend_file+0x2f6/0x14c0 fs/hfs/extent.c:401
hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
hfs_cat_create+0x1c5/0x730 fs/hfs/catalog.c:104
hfs_mkdir+0x6c/0xe0 fs/hfs/dir.c:232
vfs_mkdir+0x52d/0x5d0 fs/namei.c:5130
do_mkdirat+0x27a/0x4b0 fs/namei.c:5164
__do_sys_mkdir fs/namei.c:5191 [inline]
__se_sys_mkdir fs/namei.c:5189 [inline]
__x64_sys_mkdir+0x6c/0x80 fs/namei.c:5189
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/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+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
hfs_extend_file+0xda/0x14c0 fs/hfs/extent.c:397
hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
__hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121
__hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174
hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
hfs_extend_file+0x31e/0x14c0 fs/hfs/extent.c:401
hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353
__block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
block_write_begin fs/buffer.c:2256 [inline]
cont_write_begin+0x789/0xb50 fs/buffer.c:2594
hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
cont_expand_zero fs/buffer.c:2522 [inline]
cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584
hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
generic_perform_write+0x29d/0x8c0 mm/filemap.c:4300
generic_file_write_iter+0x118/0x550 mm/filemap.c:4443
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5d5/0xb40 fs/read_write.c:686
ksys_pwrite64 fs/read_write.c:793 [inline]
__do_sys_pwrite64 fs/read_write.c:801 [inline]
__se_sys_pwrite64 fs/read_write.c:798 [inline]
__x64_sys_pwrite64+0x196/0x220 fs/read_write.c:798
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/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.4.1268/15758:
#0: ffff888052ae6480 (sb_writers#20){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2682 [inline]
#0: ffff888052ae6480 (sb_writers#20){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff888032033d00 (&sb->s_type->i_mutex_key#26){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff888032033d00 (&sb->s_type->i_mutex_key#26){+.+.}-{4:4}, at: generic_file_write_iter+0xec/0x550 mm/filemap.c:4440
#2: ffff888032033b28 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x14c0 fs/hfs/extent.c:397
#3: ffff888050cfe0a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x2c0 fs/hfs/bfind.c:-1
stack backtrace:
CPU: 0 UID: 0 PID: 15758 Comm: syz.4.1268 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043
check_noncircular+0x12e/0x150 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+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
hfs_extend_file+0xda/0x14c0 fs/hfs/extent.c:397
hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
__hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121
__hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174
hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
hfs_extend_file+0x31e/0x14c0 fs/hfs/extent.c:401
hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353
__block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
block_write_begin fs/buffer.c:2256 [inline]
cont_write_begin+0x789/0xb50 fs/buffer.c:2594
hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
cont_expand_zero fs/buffer.c:2522 [inline]
cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584
hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
generic_perform_write+0x29d/0x8c0 mm/filemap.c:4300
generic_file_write_iter+0x118/0x550 mm/filemap.c:4443
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5d5/0xb40 fs/read_write.c:686
ksys_pwrite64 fs/read_write.c:793 [inline]
__do_sys_pwrite64 fs/read_write.c:801 [inline]
__se_sys_pwrite64 fs/read_write.c:798 [inline]
__x64_sys_pwrite64+0x196/0x220 fs/read_write.c:798
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdb7e16f749
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:00007fdb7c3ce038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007fdb7e3c5fa0 RCX: 00007fdb7e16f749
RDX: 0000000000000001 RSI: 0000200000000140 RDI: 0000000000000006
RBP: 00007fdb7e1f3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000008080c61 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdb7e3c6038 R14: 00007fdb7e3c5fa0 R15: 00007ffec77a5eb8
------------[ cut here ]------------
rtmutex deadlock detected
WARNING: kernel/locking/rtmutex.c:1674 at 0x0, CPU#0: syz.4.1268/15758
Modules linked in:
CPU: 0 UID: 0 PID: 15758 Comm: syz.4.1268 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1674
Code: 90 90 90 90 90 90 90 90 90 41 57 41 56 41 55 41 54 53 83 ff dd 0f 85 86 00 00 00 48 89 f7 e8 a6 3b 01 00 48 8d 3d 9f 08 1a 04 <67> 48 0f b9 3a 4c 8d 3d 00 00 00 00 65 48 8b 1c 25 08 80 a9 91 4c
RSP: 0018:ffffc90003f66c10 EFLAGS: 00010286
RAX: 0000000080000000 RBX: ffffc90003f66ca0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8b3e7e60 RDI: ffffffff8edc6020
RBP: ffffc90003f66da8 R08: ffffffff8ed94377 R09: 1ffffffff1db286e
R10: dffffc0000000000 R11: fffffbfff1db286f R12: 1ffff920007ecd90
R13: ffffffff8ac25269 R14: ffff888050cfe048 R15: dffffc0000000000
FS: 00007fdb7c3ce6c0(0000) GS:ffff888126d88000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdb7bb45f98 CR3: 000000005034e000 CR4: 00000000003526f0
Call Trace:
__rt_mutex_slowlock kernel/locking/rtmutex.c:1734 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
rt_mutex_slowlock+0x666/0x6b0 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline]
mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:552
hfs_find_init+0x18e/0x2c0 fs/hfs/bfind.c:-1
hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
hfs_extend_file+0x2f6/0x14c0 fs/hfs/extent.c:401
hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
__hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121
__hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174
hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
hfs_extend_file+0x31e/0x14c0 fs/hfs/extent.c:401
hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353
__block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
block_write_begin fs/buffer.c:2256 [inline]
cont_write_begin+0x789/0xb50 fs/buffer.c:2594
hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
cont_expand_zero fs/buffer.c:2522 [inline]
cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584
hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:52
generic_perform_write+0x29d/0x8c0 mm/filemap.c:4300
generic_file_write_iter+0x118/0x550 mm/filemap.c:4443
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5d5/0xb40 fs/read_write.c:686
ksys_pwrite64 fs/read_write.c:793 [inline]
__do_sys_pwrite64 fs/read_write.c:801 [inline]
__se_sys_pwrite64 fs/read_write.c:798 [inline]
__x64_sys_pwrite64+0x196/0x220 fs/read_write.c:798
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdb7e16f749
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:00007fdb7c3ce038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007fdb7e3c5fa0 RCX: 00007fdb7e16f749
RDX: 0000000000000001 RSI: 0000200000000140 RDI: 0000000000000006
RBP: 00007fdb7e1f3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000008080c61 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdb7e3c6038 R14: 00007fdb7e3c5fa0 R15: 00007ffec77a5eb8
----------------
Code disassembly (best guess):
0: 90 nop
1: 90 nop
2: 90 nop
3: 90 nop
4: 90 nop
5: 90 nop
6: 90 nop
7: 90 nop
8: 90 nop
9: 41 57 push %r15
b: 41 56 push %r14
d: 41 55 push %r13
f: 41 54 push %r12
11: 53 push %rbx
12: 83 ff dd cmp $0xffffffdd,%edi
15: 0f 85 86 00 00 00 jne 0xa1
1b: 48 89 f7 mov %rsi,%rdi
1e: e8 a6 3b 01 00 call 0x13bc9
23: 48 8d 3d 9f 08 1a 04 lea 0x41a089f(%rip),%rdi # 0x41a08c9
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 4c 8d 3d 00 00 00 00 lea 0x0(%rip),%r15 # 0x36
36: 65 48 8b 1c 25 08 80 mov %gs:0xffffffff91a98008,%rbx
3d: a9 91
3f: 4c rex.WR