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
mm/slub.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
mm/util.c | 162 ------------------------------------------------------
2 files changed, 162 insertions(+), 162 deletions(-)
--
2.25.1
