[PATCH] crypto: Replace strlcpy with strscpy

[Azeem Shaikh]

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 -E2BIG
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@xxxxxxxxx>
---
 crypto/lrw.c |    4 ++--
 crypto/xts.c |    4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/crypto/lrw.c b/crypto/lrw.c
index 1b0f76ba3eb5..bb8c1575645b 100644
--- a/crypto/lrw.c
+++ b/crypto/lrw.c
@@ -359,8 +359,8 @@ static int lrw_create(struct crypto_template *tmpl, struct rtattr **tb)
 	if (!strncmp(cipher_name, "ecb(", 4)) {
 		unsigned len;
 
-		len = strlcpy(ecb_name, cipher_name + 4, sizeof(ecb_name));
-		if (len < 2 || len >= sizeof(ecb_name))
+		len = strscpy(ecb_name, cipher_name + 4, sizeof(ecb_name));
+		if (len < 2)
 			goto err_free_inst;
 
 		if (ecb_name[len - 1] != ')')
diff --git a/crypto/xts.c b/crypto/xts.c
index 09be909a6a1a..8a9f9653426e 100644
--- a/crypto/xts.c
+++ b/crypto/xts.c
@@ -398,8 +398,8 @@ static int xts_create(struct crypto_template *tmpl, struct rtattr **tb)
 	if (!strncmp(cipher_name, "ecb(", 4)) {
 		unsigned len;
 
-		len = strlcpy(ctx->name, cipher_name + 4, sizeof(ctx->name));
-		if (len < 2 || len >= sizeof(ctx->name))
+		len = strscpy(ctx->name, cipher_name + 4, sizeof(ctx->name));
+		if (len < 2)
 			goto err_free_inst;
 
 		if (ctx->name[len - 1] != ')')
-- 
2.41.0.162.gfafddb0af9-goog