=====================================================
BUG: KMSAN: uninit-value in __hfs_ext_read_extent fs/hfs/extent.c:160 [inline]
BUG: KMSAN: uninit-value in __hfs_ext_cache_extent+0x677/0x7f0 fs/hfs/extent.c:179
 __hfs_ext_read_extent fs/hfs/extent.c:160 [inline]
 __hfs_ext_cache_extent+0x677/0x7f0 fs/hfs/extent.c:179
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x451/0x1b00 fs/hfs/extent.c:401
 hfs_get_block+0x435/0x1150 fs/hfs/extent.c:353
 __block_write_begin_int+0xaab/0x3000 fs/buffer.c:2151
 block_write_begin fs/buffer.c:2262 [inline]
 cont_write_begin+0x10df/0x1ba0 fs/buffer.c:2601
 hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52
 cont_expand_zero fs/buffer.c:2528 [inline]
 cont_write_begin+0x35a/0x1ba0 fs/buffer.c:2591
 hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52
 hfs_file_truncate+0x1d6/0xe60 fs/hfs/extent.c:494
 hfs_inode_setattr+0x964/0xaa0 fs/hfs/inode.c:654
 notify_change+0x1990/0x1aa0 fs/attr.c:552
 do_truncate+0x224/0x2a0 fs/open.c:65
 vfs_truncate+0x921/0x9d0 fs/open.c:115
 do_sys_truncate+0x103/0x240 fs/open.c:138
 __do_compat_sys_truncate fs/open.c:156 [inline]
 __se_compat_sys_truncate fs/open.c:154 [inline]
 __ia32_compat_sys_truncate+0x77/0xc0 fs/open.c:154
 ia32_sys_call+0xa11/0x42c0 arch/x86/include/generated/asm/syscalls_32.h:93
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:369
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4153 [inline]
 slab_alloc_node mm/slub.c:4196 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_noprof+0x95f/0x1310 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 hfs_find_init+0x93/0x260 fs/hfs/bfind.c:21
 hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
 hfs_extend_file+0x3c7/0x1b00 fs/hfs/extent.c:401
 hfs_get_block+0x435/0x1150 fs/hfs/extent.c:353
 __block_write_begin_int+0xaab/0x3000 fs/buffer.c:2151
 block_write_begin fs/buffer.c:2262 [inline]
 cont_write_begin+0x10df/0x1ba0 fs/buffer.c:2601
 hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52
 cont_expand_zero fs/buffer.c:2528 [inline]
 cont_write_begin+0x35a/0x1ba0 fs/buffer.c:2591
 hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52
 hfs_file_truncate+0x1d6/0xe60 fs/hfs/extent.c:494
 hfs_inode_setattr+0x964/0xaa0 fs/hfs/inode.c:654
 notify_change+0x1990/0x1aa0 fs/attr.c:552
 do_truncate+0x224/0x2a0 fs/open.c:65
 vfs_truncate+0x921/0x9d0 fs/open.c:115
 do_sys_truncate+0x103/0x240 fs/open.c:138
 __do_compat_sys_truncate fs/open.c:156 [inline]
 __se_compat_sys_truncate fs/open.c:154 [inline]
 __ia32_compat_sys_truncate+0x77/0xc0 fs/open.c:154
 ia32_sys_call+0xa11/0x42c0 arch/x86/include/generated/asm/syscalls_32.h:93
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:369
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

CPU: 1 UID: 0 PID: 19308 Comm: syz.0.3822 Not tainted 6.15.0-rc7-syzkaller-00142-g4856ebd99715 #0 PREEMPT(undef) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
=====================================================