Linux Security Modules development
 help / color / mirror / Atom feed
From: Thomas Huth <thuth@redhat.com>
To: Eric Biggers <ebiggers@kernel.org>,
	"Jason A. Donenfeld" <Jason@zx2c4.com>,
	Ard Biesheuvel <ardb@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
	"David S. Miller" <davem@davemloft.net>,
	James Bottomley <James.Bottomley@HansenPartnership.com>,
	Jarkko Sakkinen <jarkko@kernel.org>,
	Mimi Zohar <zohar@linux.ibm.com>,
	David Howells <dhowells@redhat.com>,
	Paul Moore <paul@paul-moore.com>,
	James Morris <jmorris@namei.org>,
	"Serge E. Hallyn" <serge@hallyn.com>,
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-integrity@vger.kernel.org, keyrings@vger.kernel.org,
	linux-security-module@vger.kernel.org
Subject: [PATCH 2/3] security: keys: trusted: always clear the hmac_sha1_ctx before returning
Date: Wed, 12 Aug 2026 18:33:35 +0200	[thread overview]
Message-ID: <20260812163336.3103835-3-thuth@redhat.com> (raw)
In-Reply-To: <20260812163336.3103835-1-thuth@redhat.com>

From: Thomas Huth <thuth@redhat.com>

Clear the hmac_sha1_ctx structure via __cleanup(hmac_sha1_zeroize_ctx)
to make sure that the function cannot leak any sensitive data on the
stack in case we return without hmac_sha1_final() here.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 security/keys/trusted-keys/trusted_tpm1.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c
index 13513819991e7..90536ae53d4a8 100644
--- a/security/keys/trusted-keys/trusted_tpm1.c
+++ b/security/keys/trusted-keys/trusted_tpm1.c
@@ -102,7 +102,7 @@ static inline void dump_tpm_buf(unsigned char *buf)
 static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
 		       unsigned int keylen, ...)
 {
-	struct hmac_sha1_ctx hmac_ctx;
+	struct hmac_sha1_ctx hmac_ctx __cleanup(hmac_sha1_zeroize_ctx);
 	va_list argp;
 	unsigned int dlen;
 	unsigned char *data;
-- 
2.55.0


  parent reply	other threads:[~2026-08-12 16:34 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-12 16:33 [PATCH 0/3] lib/crypto: Provide a function for zeroizing hmac_sha1_ctx Thomas Huth
2026-08-12 16:33 ` [PATCH 1/3] crypto: Provide a wrapper " Thomas Huth
2026-08-12 16:33 ` Thomas Huth [this message]
2026-08-12 16:33 ` [PATCH 3/3] lib/crypto: sha1: Use hmac_sha1_zeroize_ctx() instead of memzero_explicit() Thomas Huth

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260812163336.3103835-3-thuth@redhat.com \
    --to=thuth@redhat.com \
    --cc=James.Bottomley@HansenPartnership.com \
    --cc=Jason@zx2c4.com \
    --cc=ardb@kernel.org \
    --cc=davem@davemloft.net \
    --cc=dhowells@redhat.com \
    --cc=ebiggers@kernel.org \
    --cc=herbert@gondor.apana.org.au \
    --cc=jarkko@kernel.org \
    --cc=jmorris@namei.org \
    --cc=keyrings@vger.kernel.org \
    --cc=linux-crypto@vger.kernel.org \
    --cc=linux-integrity@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=paul@paul-moore.com \
    --cc=serge@hallyn.com \
    --cc=zohar@linux.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox