loop2: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.2.119/6699 is trying to acquire lock: ffff88805bd520e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_free+0xc7/0x5f0 fs/hfsplus/bitmap.c:182 but task is already holding lock: ffff888023a83cf8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_truncate+0x2a4/0xc70 fs/hfsplus/extents.c:573 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547 hfsplus_get_block+0x39a/0x15e0 fs/hfsplus/extents.c:260 block_read_full_folio+0x29f/0x830 fs/buffer.c:2420 filemap_read_folio+0x117/0x380 mm/filemap.c:2444 do_read_cache_folio+0x2ba/0x560 mm/filemap.c:4036 do_read_cache_page mm/filemap.c:4102 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:4111 read_mapping_page include/linux/pagemap.h:993 [inline] hfsplus_block_allocate+0xf3/0xc40 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xa9a/0x1ba0 fs/hfsplus/extents.c:464 hfsplus_get_block+0x40c/0x15e0 fs/hfsplus/extents.c:245 __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 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 cont_expand_zero fs/buffer.c:2555 [inline] cont_write_begin+0x828/0xb50 fs/buffer.c:2584 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 generic_perform_write+0x29d/0x8c0 mm/filemap.c:4254 generic_file_write_iter+0x118/0x550 mm/filemap.c:4397 do_iter_readv_writev+0x635/0x8d0 fs/read_write.c:-1 vfs_writev+0x323/0x970 fs/read_write.c:1057 do_pwritev fs/read_write.c:1153 [inline] __do_sys_pwritev2 fs/read_write.c:1211 [inline] __se_sys_pwritev2+0x17c/0x2a0 fs/read_write.c:1202 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&sbi->alloc_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547 hfsplus_block_free+0xc7/0x5f0 fs/hfsplus/bitmap.c:182 hfsplus_free_extents+0x121/0xa50 fs/hfsplus/extents.c:360 hfsplus_file_truncate+0x754/0xc70 fs/hfsplus/extents.c:588 hfsplus_setattr+0x1c4/0x270 fs/hfsplus/inode.c:266 notify_change+0xc18/0xf60 fs/attr.c:546 do_truncate+0x1a4/0x220 fs/open.c:68 vfs_truncate+0x493/0x520 fs/open.c:118 do_sys_truncate+0xdb/0x190 fs/open.c:141 __do_sys_truncate fs/open.c:153 [inline] __se_sys_truncate fs/open.c:151 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:151 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 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(&HFSPLUS_I(inode)->extents_lock); lock(&sbi->alloc_mutex); lock(&HFSPLUS_I(inode)->extents_lock); lock(&sbi->alloc_mutex); *** DEADLOCK *** 3 locks held by syz.2.119/6699: #0: ffff88805bb06480 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff888023a83f58 (&sb->s_type->i_mutex_key#29){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:985 [inline] #1: ffff888023a83f58 (&sb->s_type->i_mutex_key#29){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63 #2: ffff888023a83cf8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_truncate+0x2a4/0xc70 fs/hfsplus/extents.c:573 stack backtrace: CPU: 0 UID: 0 PID: 6699 Comm: syz.2.119 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+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 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+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547 hfsplus_block_free+0xc7/0x5f0 fs/hfsplus/bitmap.c:182 hfsplus_free_extents+0x121/0xa50 fs/hfsplus/extents.c:360 hfsplus_file_truncate+0x754/0xc70 fs/hfsplus/extents.c:588 hfsplus_setattr+0x1c4/0x270 fs/hfsplus/inode.c:266 notify_change+0xc18/0xf60 fs/attr.c:546 do_truncate+0x1a4/0x220 fs/open.c:68 vfs_truncate+0x493/0x520 fs/open.c:118 do_sys_truncate+0xdb/0x190 fs/open.c:141 __do_sys_truncate fs/open.c:153 [inline] __se_sys_truncate fs/open.c:151 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:151 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f087d29f6c9 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:00007f087b4fe038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f087d4f5fa0 RCX: 00007f087d29f6c9 RDX: 0000000000000000 RSI: 0200000080000000 RDI: 0000200000000080 RBP: 00007f087d321f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f087d4f6038 R14: 00007f087d4f5fa0 R15: 00007ffc65285528