From: Azeem Shaikh <azeemshaikh38@xxxxxxxxx> [ Upstream commit babb80b3ecc6f40c962e13c654ebcd27f25ee327 ] 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@xxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- crypto/lrw.c | 6 +++--- crypto/xts.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/crypto/lrw.c b/crypto/lrw.c index 1b0f76ba3eb5e..59260aefed280 100644 --- a/crypto/lrw.c +++ b/crypto/lrw.c @@ -357,10 +357,10 @@ static int lrw_create(struct crypto_template *tmpl, struct rtattr **tb) * cipher name. */ if (!strncmp(cipher_name, "ecb(", 4)) { - unsigned len; + int 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 09be909a6a1aa..548b302c6c6a0 100644 --- a/crypto/xts.c +++ b/crypto/xts.c @@ -396,10 +396,10 @@ static int xts_create(struct crypto_template *tmpl, struct rtattr **tb) * cipher name. */ if (!strncmp(cipher_name, "ecb(", 4)) { - unsigned len; + int 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] != ')') -- 2.40.1
