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>
---
 arch/hexagon/kernel/setup.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/hexagon/kernel/setup.c b/arch/hexagon/kernel/setup.c
index 1880d9beaf2b..621674e86232 100644
--- a/arch/hexagon/kernel/setup.c
+++ b/arch/hexagon/kernel/setup.c
@@ -66,9 +66,9 @@ void __init setup_arch(char **cmdline_p)
 		on_simulator = 0;
 
 	if (p[0] != '\0')
-		strlcpy(boot_command_line, p, COMMAND_LINE_SIZE);
+		strscpy(boot_command_line, p, COMMAND_LINE_SIZE);
 	else
-		strlcpy(boot_command_line, default_command_line,
+		strscpy(boot_command_line, default_command_line,
 			COMMAND_LINE_SIZE);
 
 	/*
@@ -76,7 +76,7 @@ void __init setup_arch(char **cmdline_p)
 	 * are both picked up by the init code. If no reason to
 	 * make them different, pass the same pointer back.
 	 */
-	strlcpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
+	strscpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
 	*cmdline_p = cmd_line;
 
 	parse_early_param();

On Tue, 30 May 2023 16:26:08 +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.
> 
> [...]

Successfully build tested with Clang 17.

Applied to for-next/hardening, thanks!

[1/1] Hexagon: Replace all non-returning strlcpy with strscpy
      https://git.kernel.org/kees/c/f0e212de87a1

-- 
Kees Cook

On Tue, May 30, 2023 at 04:26:08PM +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.
> 
> [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>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook