From: Kees Cook <kees@kernel.org>
To: Thorsten Blum <thorsten.blum@linux.dev>
Cc: Mimi Zohar <zohar@linux.ibm.com>,
David Howells <dhowells@redhat.com>,
Jarkko Sakkinen <jarkko@kernel.org>,
Paul Moore <paul@paul-moore.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
linux-hardening@vger.kernel.org, linux-integrity@vger.kernel.org,
keyrings@vger.kernel.org, linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] keys: Replace deprecated strncpy in ecryptfs_fill_auth_tok
Date: Fri, 10 Oct 2025 08:12:28 -0700 [thread overview]
Message-ID: <202510100808.E634CF9@keescook> (raw)
In-Reply-To: <20251009180316.394708-3-thorsten.blum@linux.dev>
On Thu, Oct 09, 2025 at 08:03:17PM +0200, Thorsten Blum wrote:
> strncpy() is deprecated for NUL-terminated destination buffers; use
> strscpy_pad() instead.
Remember for strncpy->strscpy conversions, the commit message needs
to include:
- how did you determine this was a NUL-terminated destination?
- how did you determine the need for padding or not?
- how do you know that final byte truncation is not a problem?
-Kees
>
> Link: https://github.com/KSPP/linux/issues/90
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
> security/keys/encrypted-keys/ecryptfs_format.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/security/keys/encrypted-keys/ecryptfs_format.c b/security/keys/encrypted-keys/ecryptfs_format.c
> index 8fdd76105ce3..2fc6f3a66135 100644
> --- a/security/keys/encrypted-keys/ecryptfs_format.c
> +++ b/security/keys/encrypted-keys/ecryptfs_format.c
> @@ -54,8 +54,7 @@ int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok,
> auth_tok->version = (((uint16_t)(major << 8) & 0xFF00)
> | ((uint16_t)minor & 0x00FF));
> auth_tok->token_type = ECRYPTFS_PASSWORD;
> - strncpy((char *)auth_tok->token.password.signature, key_desc,
> - ECRYPTFS_PASSWORD_SIG_SIZE);
> + strscpy_pad(auth_tok->token.password.signature, key_desc);
> auth_tok->token.password.session_key_encryption_key_bytes =
> ECRYPTFS_MAX_KEY_BYTES;
> /*
> --
> 2.51.0
>
>
--
Kees Cook
prev parent reply other threads:[~2025-10-10 15:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-09 18:03 [PATCH] keys: Replace deprecated strncpy in ecryptfs_fill_auth_tok Thorsten Blum
2025-10-10 3:40 ` Jarkko Sakkinen
2025-10-10 15:12 ` Kees Cook [this message]
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