m68k: emu: Replace strlcpy() with strscpy()

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().

Direct replacement is safe here since return value of -errno
is used to check for truncation instead of sizeof(dest).

[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>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20230830185428.4109426-1-azeemshaikh38@gmail.com
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/arch/m68k/emu/natfeat.c b/arch/m68k/emu/natfeat.c
index b19dc00026d9..d124c62022c2 100644
--- a/arch/m68k/emu/natfeat.c
+++ b/arch/m68k/emu/natfeat.c
@@ -42,10 +42,10 @@ long nf_get_id(const char *feature_name)
 {
 	/* feature_name may be in vmalloc()ed memory, so make a copy */
 	char name_copy[32];
-	size_t n;
+	ssize_t n;
 
-	n = strlcpy(name_copy, feature_name, sizeof(name_copy));
-	if (n >= sizeof(name_copy))
+	n = strscpy(name_copy, feature_name, sizeof(name_copy));
+	if (n < 0)
 		return 0;
 
 	return nf_get_id_phys(virt_to_phys(name_copy));