[syzbot] [hfs?] KMSAN: uninit-value in __hfsplus_ext_cache_extent

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    fbafc3e621c3 Merge tag 'for_linus' of git://git.kernel.org..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1770ee26e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e0c7078a6b901aa3
dashboard link: https://syzkaller.appspot.com/bug?extid=55ad87f38795d6787521
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17ea9be9e80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=149e8179e80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1520f7b6daa4/disk-fbafc3e6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8b490af009d5/vmlinux-fbafc3e6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/202ca200f4a4/bzImage-fbafc3e6.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/78ed00b58340/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+55ad87f38795d6787521@xxxxxxxxxxxxxxxxxxxxxxxxx

=====================================================
BUG: KMSAN: uninit-value in __hfsplus_ext_read_extent fs/hfsplus/extents.c:167 [inline]
BUG: KMSAN: uninit-value in __hfsplus_ext_cache_extent+0x82a/0x960 fs/hfsplus/extents.c:191
 __hfsplus_ext_read_extent fs/hfsplus/extents.c:167 [inline]
 __hfsplus_ext_cache_extent+0x82a/0x960 fs/hfsplus/extents.c:191
 hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline]
 hfsplus_file_extend+0x775/0x1b90 fs/hfsplus/extents.c:461
 hfsplus_get_block+0xe99/0x1690 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x946/0x2c70 fs/buffer.c:2119
 __block_write_begin fs/buffer.c:2168 [inline]
 block_write_begin+0x143/0x450 fs/buffer.c:2227
 cont_write_begin+0xd5c/0x12f0 fs/buffer.c:2582
 hfsplus_write_begin+0x9a/0x130 fs/hfsplus/inode.c:52
 generic_perform_write+0x3f5/0xc40 mm/filemap.c:3918
 __generic_file_write_iter+0x20a/0x460 mm/filemap.c:4013
 generic_file_write_iter+0x103/0x5b0 mm/filemap.c:4039
 call_write_iter include/linux/fs.h:2020 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x8ef/0x1490 fs/read_write.c:584
 ksys_write+0x20f/0x4c0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x93/0xd0 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Uninit was created at:
 slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768
 slab_alloc_node mm/slub.c:3478 [inline]
 __kmem_cache_alloc_node+0x5c9/0x970 mm/slub.c:3517
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc+0x121/0x3c0 mm/slab_common.c:1020
 kmalloc include/linux/slab.h:604 [inline]
 hfsplus_find_init+0x91/0x250 fs/hfsplus/bfind.c:21
 hfsplus_ext_read_extent fs/hfsplus/extents.c:216 [inline]
 hfsplus_file_extend+0x6d8/0x1b90 fs/hfsplus/extents.c:461
 hfsplus_get_block+0xe99/0x1690 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x946/0x2c70 fs/buffer.c:2119
 __block_write_begin fs/buffer.c:2168 [inline]
 block_write_begin+0x143/0x450 fs/buffer.c:2227
 cont_write_begin+0xd5c/0x12f0 fs/buffer.c:2582
 hfsplus_write_begin+0x9a/0x130 fs/hfsplus/inode.c:52
 generic_perform_write+0x3f5/0xc40 mm/filemap.c:3918
 __generic_file_write_iter+0x20a/0x460 mm/filemap.c:4013
 generic_file_write_iter+0x103/0x5b0 mm/filemap.c:4039
 call_write_iter include/linux/fs.h:2020 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x8ef/0x1490 fs/read_write.c:584
 ksys_write+0x20f/0x4c0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x93/0xd0 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

CPU: 0 PID: 5003 Comm: syz-executor371 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
=====================================================


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