[PATCH v3 0/2] Refine kmalloc caches randomization in kvmalloc

[GONG Ruiqi <gongruiqi1@huawei.com>]

Hi,

v3:
  - move all the way from kmalloc_gfp_adjust to kvrealloc_noprof into
    mm/slub.c
  - some rewording for commit logs
v2: https://lore.kernel.org/all/20250208014723.1514049-1-gongruiqi1@huawei.com/
  - change the implementation as Vlastimil suggested
v1: https://lore.kernel.org/all/20250122074817.991060-1-gongruiqi1@huawei.com/

Tamás reported [1] that kmalloc cache randomization doesn't actually
work for those kmalloc invoked via kvmalloc. For more details, see the
commit log of patch 2.

The current solution requires a direct call from __kvmalloc_node_noprof
to __do_kmalloc_node, a static function in a different .c file. As
suggested by Vlastimil [2], it's achieved by simply moving
__kvmalloc_node_noprof from mm/util.c to mm/slub.c, together with some
other functions of the same family.

Link: https://github.com/google/security-research/blob/908d59b573960dc0b90adda6f16f7017aca08609/pocs/linux/kernelctf/CVE-2024-27397_mitigation/docs/exploit.md?plain=1#L259 [1]
Link: https://lore.kernel.org/all/62044279-0c56-4185-97f7-7afac65ff449@suse.cz/ [2]

GONG Ruiqi (2):
  slab: Adjust placement of __kvmalloc_node_noprof
  slab: Achieve better kmalloc caches randomization in kvmalloc

 mm/slub.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 mm/util.c | 162 ------------------------------------------------------
 2 files changed, 162 insertions(+), 162 deletions(-)

-- 
2.25.1