loop6: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected 6.1.135-syzkaller #0 Not tainted ------------------------------------------------------ syz.6.1619/13183 is trying to acquire lock: ffff888059f18108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x39b/0x1530 fs/hfsplus/extents.c:260 but task is already holding lock: ffff88807c3168f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x99/0x8e0 fs/hfsplus/bitmap.c:35 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sbi->alloc_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747 hfsplus_block_allocate+0x99/0x8e0 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xa8e/0x1950 fs/hfsplus/extents.c:469 hfsplus_bmap_reserve+0x11e/0x4f0 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x180/0x1020 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x12f6/0x1b90 fs/hfsplus/super.c:560 mount_bdev+0x287/0x3c0 fs/super.c:1443 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3057 do_mount fs/namespace.c:3400 [inline] __do_sys_mount fs/namespace.c:3608 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3585 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&HFSPLUS_I(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+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747 hfsplus_get_block+0x39b/0x1530 fs/hfsplus/extents.c:260 block_read_full_folio+0x3c9/0xed0 fs/buffer.c:2271 filemap_read_folio+0x160/0x760 mm/filemap.c:2490 do_read_cache_folio+0x2a0/0x760 mm/filemap.c:3627 do_read_cache_page+0x32/0x220 mm/filemap.c:3669 read_mapping_page include/linux/pagemap.h:791 [inline] hfsplus_block_allocate+0xfb/0x8e0 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xa8e/0x1950 fs/hfsplus/extents.c:469 hfsplus_get_block+0x40e/0x1530 fs/hfsplus/extents.c:245 __block_write_begin_int+0x54b/0x1a70 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin+0x96/0x1e0 fs/buffer.c:2102 cont_write_begin+0x5c4/0x7d0 fs/buffer.c:2456 hfsplus_write_begin+0x87/0xd0 fs/hfsplus/inode.c:52 generic_perform_write+0x2db/0x560 mm/filemap.c:3846 __generic_file_write_iter+0x172/0x430 mm/filemap.c:3974 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:4006 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x44c/0x960 fs/read_write.c:584 ksys_write+0x143/0x240 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 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(&sbi->alloc_mutex); lock(&HFSPLUS_I(inode)->extents_lock); lock(&sbi->alloc_mutex); lock(&HFSPLUS_I(inode)->extents_lock); *** DEADLOCK *** 5 locks held by syz.6.1619/13183: #0: ffff888065ebd268 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1040 #1: ffff888059954460 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580 #2: ffff888059f1ef00 (&sb->s_type->i_mutex_key#29){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #2: ffff888059f1ef00 (&sb->s_type->i_mutex_key#29){+.+.}-{3:3}, at: generic_file_write_iter+0x7f/0x2e0 mm/filemap.c:4003 #3: ffff888059f1ed08 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1b3/0x1950 fs/hfsplus/extents.c:458 #4: ffff88807c3168f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x99/0x8e0 fs/hfsplus/bitmap.c:35 stack backtrace: CPU: 0 PID: 13183 Comm: syz.6.1619 Not tainted 6.1.135-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 check_noncircular+0x274/0x310 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+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747 hfsplus_get_block+0x39b/0x1530 fs/hfsplus/extents.c:260 block_read_full_folio+0x3c9/0xed0 fs/buffer.c:2271 filemap_read_folio+0x160/0x760 mm/filemap.c:2490 do_read_cache_folio+0x2a0/0x760 mm/filemap.c:3627 do_read_cache_page+0x32/0x220 mm/filemap.c:3669 read_mapping_page include/linux/pagemap.h:791 [inline] hfsplus_block_allocate+0xfb/0x8e0 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xa8e/0x1950 fs/hfsplus/extents.c:469 hfsplus_get_block+0x40e/0x1530 fs/hfsplus/extents.c:245 __block_write_begin_int+0x54b/0x1a70 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin+0x96/0x1e0 fs/buffer.c:2102 cont_write_begin+0x5c4/0x7d0 fs/buffer.c:2456 hfsplus_write_begin+0x87/0xd0 fs/hfsplus/inode.c:52 generic_perform_write+0x2db/0x560 mm/filemap.c:3846 __generic_file_write_iter+0x172/0x430 mm/filemap.c:3974 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:4006 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x44c/0x960 fs/read_write.c:584 ksys_write+0x143/0x240 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fe7b7f8e969 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:00007fe7b8ee9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fe7b81b5fa0 RCX: 00007fe7b7f8e969 RDX: 000000000208e24b RSI: 0000200000000040 RDI: 0000000000000004 RBP: 00007fe7b8010ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe7b81b5fa0 R15: 00007ffc7977a6c8