syzbot

loop0: detected capacity change from 0 to 64
=====================================================
BUG: KMSAN: uninit-value in hfs_find_set_zero_bits+0x836/0xca0 fs/hfs/bitmap.c:45
 hfs_find_set_zero_bits+0x836/0xca0 fs/hfs/bitmap.c:45
 hfs_vbm_search_free+0x141/0x530 fs/hfs/bitmap.c:151
 hfs_extend_file+0x69e/0x19f0 fs/hfs/extent.c:408
 hfs_get_block+0x3d8/0xf50 fs/hfs/extent.c:353
 __block_write_begin_int+0xa6b/0x2f80 fs/buffer.c:2121
 block_write_begin fs/buffer.c:2231 [inline]
 cont_write_begin+0xf82/0x1940 fs/buffer.c:2582
 hfs_write_begin+0x85/0x120 fs/hfs/inode.c:52
 cont_expand_zero fs/buffer.c:2509 [inline]
 cont_write_begin+0x32f/0x1940 fs/buffer.c:2572
 hfs_write_begin+0x85/0x120 fs/hfs/inode.c:52
 hfs_file_truncate+0x1a5/0xd30 fs/hfs/extent.c:494
 hfs_inode_setattr+0x998/0xab0 fs/hfs/inode.c:654
 notify_change+0x1a8e/0x1b80 fs/attr.c:503
 do_truncate+0x22a/0x2b0 fs/open.c:65
 vfs_truncate+0x5d4/0x680 fs/open.c:111
 do_sys_truncate+0x104/0x240 fs/open.c:134
 __do_sys_truncate fs/open.c:146 [inline]
 __se_sys_truncate fs/open.c:144 [inline]
 __x64_sys_truncate+0x6c/0xa0 fs/open.c:144
 x64_sys_call+0x2ce3/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:77
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4091 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 __kmalloc_cache_noprof+0x4f0/0xb00 mm/slub.c:4290
 kmalloc_noprof include/linux/slab.h:878 [inline]
 hfs_mdb_get+0x1bd4/0x28b0 fs/hfs/mdb.c:175
 hfs_fill_super+0x1cf6/0x23c0 fs/hfs/super.c:407
 mount_bdev+0x39a/0x520 fs/super.c:1679
 hfs_mount+0x4d/0x60 fs/hfs/super.c:457
 legacy_get_tree+0x114/0x290 fs/fs_context.c:662
 vfs_get_tree+0xb1/0x5a0 fs/super.c:1800
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3507
 path_mount+0x742/0x1f10 fs/namespace.c:3834
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x722/0x810 fs/namespace.c:4034
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4034
 x64_sys_call+0x255a/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 5788 Comm: syz-executor210 Not tainted 6.12.0-rc5-syzkaller-00044-gc1e939a21eb1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
=====================================================