GHSA-64p7-wm49-vgg4 
In the Linux kernel, the following vulnerability has been resolved:hfsplus: don't query the device logical block size multiple timesDevices block sizes may change. One of these cases is a loop device by
using ioctl LOOP_SET_BLOCK_SIZE.While this may cause other issues like IO being rejected, in the case of
hfsplus, it will allocate a block by using that size and potentially write
out-of-bounds when hfsplus_read_wrapper calls hfsplus_submit_bio and the
latter function reads a different io_size.Using a new min_io_size initally set to sb_min_blocksize works for the
purposes of the original fix, since it will be set to the max between
HFSPLUS_SECTOR_SIZE and the first seen logical block size. We still use the
max between HFSPLUS_SECTOR_SIZE and min_io_size in case the latter is not
initialized.Tested by mounting an hfsplus filesystem with loop block sizes 512, 1024
and 4096.The produced KASAN report before the fix looks like this:[  419.944641] ==================================================================
[  419.945655] BUG: KASAN: slab-use-after-free in hfsplus_read_wrapper+0x659/0xa0a
[  419.946703] Read of size 2 at addr ffff88800721fc00 by task repro/10678
[  419.947612]
[  419.947846] CPU: 0 UID: 0 PID: 10678 Comm: repro Not tainted 6.12.0-rc5-00008-gdf56e0f2f3ca #84
[  419.949007] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
[  419.950035] Call Trace:
[  419.950384]  <TASK>
[  419.950676]  dump_stack_lvl+0x57/0x78
[  419.951212]  ? hfsplus_read_wrapper+0x659/0xa0a
[  419.951830]  print_report+0x14c/0x49e
[  419.952361]  ? __virt_addr_valid+0x267/0x278
[  419.952979]  ? kmem_cache_debug_flags+0xc/0x1d
[  419.953561]  ? hfsplus_read_wrapper+0x659/0xa0a
[  419.954231]  kasan_report+0x89/0xb0
[  419.954748]  ? hfsplus_read_wrapper+0x659/0xa0a
[  419.955367]  hfsplus_read_wrapper+0x659/0xa0a
[  419.955948]  ? __pfx_hfsplus_read_wrapper+0x10/0x10
[  419.956618]  ? do_raw_spin_unlock+0x59/0x1a9
[  419.957214]  ? _raw_spin_unlock+0x1a/0x2e
[  419.957772]  hfsplus_fill_super+0x348/0x1590
[  419.958355]  ? hlock_class+0x4c/0x109
[  419.958867]  ? __pfx_hfsplus_fill_super+0x10/0x10
[  419.959499]  ? __pfx_string+0x10/0x10
[  419.960006]  ? lock_acquire+0x3e2/0x454
[  419.960532]  ? bdev_name.constprop.0+0xce/0x243
[  419.961129]  ? __pfx_bdev_name.constprop.0+0x10/0x10
[  419.961799]  ? pointer+0x3f0/0x62f
[  419.962277]  ? __pfx_pointer+0x10/0x10
[  419.962761]  ? vsnprintf+0x6c4/0xfba
[  419.963178]  ? __pfx_vsnprintf+0x10/0x10
[  419.963621]  ? setup_bdev_super+0x376/0x3b3
[  419.964029]  ? snprintf+0x9d/0xd2
[  419.964344]  ? __pfx_snprintf+0x10/0x10
[  419.964675]  ? lock_acquired+0x45c/0x5e9
[  419.965016]  ? set_blocksize+0x139/0x1c1
[  419.965381]  ? sb_set_blocksize+0x6d/0xae
[  419.965742]  ? __pfx_hfsplus_fill_super+0x10/0x10
[  419.966179]  mount_bdev+0x12f/0x1bf
[  419.966512]  ? __pfx_mount_bdev+0x10/0x10
[  419.966886]  ? vfs_parse_fs_string+0xce/0x111
[  419.967293]  ? __pfx_vfs_parse_fs_string+0x10/0x10
[  419.967702]  ? __pfx_hfsplus_mount+0x10/0x10
[  419.968073]  legacy_get_tree+0x104/0x178
[  419.968414]  vfs_get_tree+0x86/0x296
[  419.968751]  path_mount+0xba3/0xd0b
[  419.969157]  ? __pfx_path_mount+0x10/0x10
[  419.969594]  ? kmem_cache_free+0x1e2/0x260
[  419.970311]  do_mount+0x99/0xe0
[  419.970630]  ? __pfx_do_mount+0x10/0x10
[  419.971008]  __do_sys_mount+0x199/0x1c9
[  419.971397]  do_syscall_64+0xd0/0x135
[  419.971761]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  419.972233] RIP: 0033:0x7c3cb812972e
[  419.972564] Code: 48 8b 0d f5 46 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d c2 46 0d 00 f7 d8 64 89 01 48
[  419.974371] RSP: 002b:00007ffe30632548 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
[  419.975048] RAX: ffffffffffffffda RBX: 00007ffe306328d8 RCX: 00007c3cb812972e
[  419.975701] RDX: 0000000020000000 RSI: 0000000020000c80 RDI:
---truncated---
CVSS v3.1 score: 7.8