Re: [PATCH v4] arm64/sysreg: refactor deprecated strncpy

[Konrad Dybcio]

On 5.09.2023 22:10, Justin Stitt wrote:
> strncpy is deprecated [1] and should not be used if the src string is
> not NUL-terminated.
> 
> When dealing with `cmdline` we are counting the number of characters
> until a space then copying these over into `buf`. Let's not use any of
> the str*() functions since the src string is not necessarily NUL-terminated.
> 
> Prefer `memcpy()` alongside a forced NUL-termination as it more
> accurately describes what is going on within this function, i.e: copying
> from non NUL-terminated buffer into a NUL-terminated buffer.
> 
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@xxxxxxxxxxxxxxx
> Suggested-by: Kees Cook <keescook@xxxxxxxxxxxx>
> Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
> ---
Hi,

some form of this patch [1] went into -next and it broke booting
on at least the Qualcomm SC8280XP-based Lenovo Thinkpad X13S.

Konrad

[1] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?h=d232606773a0b09ec7f1ffc25f63abe801d011fd