Bug 2420355 (CVE-2022-50657)

Summary: CVE-2022-50657 kernel: riscv: mm: add missing memcpy in kasan_init
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2025-12-09 02:05:13 UTC
In the Linux kernel, the following vulnerability has been resolved:

riscv: mm: add missing memcpy in kasan_init

Hi Atish,

It seems that the panic is due to the missing memcpy during kasan_init.
Could you please check whether this patch is helpful?

When doing kasan_populate, the new allocated base_pud/base_p4d should
contain kasan_early_shadow_{pud, p4d}'s content. Add the missing memcpy
to avoid page fault when read/write kasan shadow region.

Tested on:
 - qemu with sv57 and CONFIG_KASAN on.
 - qemu with sv48 and CONFIG_KASAN on.