* [PATCH] clocksource: Replace all non-returning strlcpy with strscpy
@ 2023-05-30 16:35 Azeem Shaikh
2023-05-30 18:16 ` John Stultz
2023-05-30 23:26 ` Kees Cook
0 siblings, 2 replies; 3+ messages in thread
From: Azeem Shaikh @ 2023-05-30 16:35 UTC (permalink / raw)
To: John Stultz, Thomas Gleixner
Cc: linux-hardening, Azeem Shaikh, Stephen Boyd, linux-kernel
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
---
kernel/time/clocksource.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 91836b727cef..88cbc1181b23 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -1480,7 +1480,7 @@ static int __init boot_override_clocksource(char* str)
{
mutex_lock(&clocksource_mutex);
if (str)
- strlcpy(override_name, str, sizeof(override_name));
+ strscpy(override_name, str, sizeof(override_name));
mutex_unlock(&clocksource_mutex);
return 1;
}
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] clocksource: Replace all non-returning strlcpy with strscpy
2023-05-30 16:35 [PATCH] clocksource: Replace all non-returning strlcpy with strscpy Azeem Shaikh
@ 2023-05-30 18:16 ` John Stultz
2023-05-30 23:26 ` Kees Cook
1 sibling, 0 replies; 3+ messages in thread
From: John Stultz @ 2023-05-30 18:16 UTC (permalink / raw)
To: Azeem Shaikh; +Cc: Thomas Gleixner, linux-hardening, Stephen Boyd, linux-kernel
On Tue, May 30, 2023 at 9:35 AM Azeem Shaikh <azeemshaikh38@gmail.com> wrote:
>
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
>
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
> ---
> kernel/time/clocksource.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
> index 91836b727cef..88cbc1181b23 100644
> --- a/kernel/time/clocksource.c
> +++ b/kernel/time/clocksource.c
> @@ -1480,7 +1480,7 @@ static int __init boot_override_clocksource(char* str)
> {
> mutex_lock(&clocksource_mutex);
> if (str)
> - strlcpy(override_name, str, sizeof(override_name));
> + strscpy(override_name, str, sizeof(override_name));
> mutex_unlock(&clocksource_mutex);
> return 1;
> }
Sounds reasonable to me.
Acked-by: John Stultz <jstultz@google.com>
Thanks for submitting this!
-john
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] clocksource: Replace all non-returning strlcpy with strscpy
2023-05-30 16:35 [PATCH] clocksource: Replace all non-returning strlcpy with strscpy Azeem Shaikh
2023-05-30 18:16 ` John Stultz
@ 2023-05-30 23:26 ` Kees Cook
1 sibling, 0 replies; 3+ messages in thread
From: Kees Cook @ 2023-05-30 23:26 UTC (permalink / raw)
To: tglx, jstultz, azeemshaikh38
Cc: Kees Cook, sboyd, linux-kernel, linux-hardening
On Tue, 30 May 2023 16:35:46 +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
>
> [...]
Applied to for-next/hardening, thanks!
[1/1] clocksource: Replace all non-returning strlcpy with strscpy
https://git.kernel.org/kees/c/40932d192ec8
--
Kees Cook
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-05-30 16:35 [PATCH] clocksource: Replace all non-returning strlcpy with strscpy Azeem Shaikh
2023-05-30 18:16 ` John Stultz
2023-05-30 23:26 ` Kees Cook
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