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

[Vlastimil Babka]

On 2/12/25 09:15, GONG Ruiqi wrote:
> 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@xxxxxxxxxx/
>   - change the implementation as Vlastimil suggested
> v1: https://lore.kernel.org/all/20250122074817.991060-1-gongruiqi1@xxxxxxxxxx/
> 
> 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@xxxxxxx/ [2]
> 
> GONG Ruiqi (2):
>   slab: Adjust placement of __kvmalloc_node_noprof
>   slab: Achieve better kmalloc caches randomization in kvmalloc

Applied to slab/for-next, thanks!

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