[PATCH] checkpatch: Check for strcpy and strncpy too

[PATCH] checkpatch: Check for strcpy and strncpy too

[Kees Cook]

Warn about strcpy(), strncpy(), and strlcpy(). Suggest strscpy() and
include pointers to the open KSPP issues for each, which has further
details and replacement procedures.

Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 scripts/checkpatch.pl | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index b30114d637c4..a90e0ede53ad 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6997,10 +6997,22 @@ sub process {
 #			}
 #		}
 
+# strcpy uses that should likely be strscpy
+		if ($line =~ /\bstrcpy\s*\(/) {
+			WARN("STRCPY",
+			     "Use of strcpy has been replaced with strscpy - see: https://github.com/KSPP/linux/issues/88\n" . $herecurr);
+		}
+
 # strlcpy uses that should likely be strscpy
 		if ($line =~ /\bstrlcpy\s*\(/) {
 			WARN("STRLCPY",
-			     "Prefer strscpy over strlcpy - see: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw\@mail.gmail.com/\n" . $herecurr);
+			     "Use of strlcpy has been replaced with strscpy - see: https://github.com/KSPP/linux/issues/89\n" . $herecurr);
+		}
+
+# strncpy uses that should likely be strscpy or strscpy_pad
+		if ($line =~ /\bstrncpy\s*\(/) {
+			WARN("STRNCPY",
+			     "Prefer strscpy, strscpy_pad, or __nonstring over strncpy - see: https://github.com/KSPP/linux/issues/90\n" . $herecurr);
 		}
 
 # typecasts on min/max could be min_t/max_t
-- 
2.34.1

Re: [PATCH] checkpatch: Check for strcpy and strncpy too

[Joe Perches]

On Wed, 2023-05-17 at 13:13 -0700, Kees Cook wrote:
> Warn about strcpy(), strncpy(), and strlcpy(). Suggest strscpy() and
> include pointers to the open KSPP issues for each, which has further
> details and replacement procedures.
> 
> Cc: Andy Whitcroft <apw@canonical.com>
> Cc: Joe Perches <joe@perches.com>
> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  scripts/checkpatch.pl | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index b30114d637c4..a90e0ede53ad 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -6997,10 +6997,22 @@ sub process {
>  #			}
>  #		}
>  
> +# strcpy uses that should likely be strscpy
> +		if ($line =~ /\bstrcpy\s*\(/) {
> +			WARN("STRCPY",
> +			     "Use of strcpy has been replaced with strscpy - see: https://github.com/KSPP/linux/issues/88\n" . $herecurr);

I would prefer something like

			"Prefer strscpy over strcpy etc..."

as there are just too many existing uses of strcpy that can not
easily be converted.

$ git grep -w strcpy -- "*.[chS]" | wc -l
2015

> +		}
> +
>  # strlcpy uses that should likely be strscpy
>  		if ($line =~ /\bstrlcpy\s*\(/) {
>  			WARN("STRLCPY",
> -			     "Prefer strscpy over strlcpy - see: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw\@mail.gmail.com/\n" . $herecurr);
> +			     "Use of strlcpy has been replaced with strscpy - see: https://github.com/KSPP/linux/issues/89\n" . $herecurr);
> +		}
> +
> +# strncpy uses that should likely be strscpy or strscpy_pad
> +		if ($line =~ /\bstrncpy\s*\(/) {
> +			WARN("STRNCPY",
> +			     "Prefer strscpy, strscpy_pad, or __nonstring over strncpy - see: https://github.com/KSPP/linux/issues/90\n" . $herecurr);
>  		}
>  
>  # typecasts on min/max could be min_t/max_t