From patchwork Mon Apr 7 12:28:05 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 14040367 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 628BB224FD; Mon, 7 Apr 2025 12:28:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744028892; cv=none; b=sl98Ap9GD+sn0E05u8XuFp7sqzG0XEZ6Ml0EdxMx3+VEVkZPmVuoyRAoWzGV0pkGRSZCCO9vcVV0tBV/iTnMlz+E7p6GoUQHGJ7SkgcBSDB1/h6AX+EOhSYreaVWco8YoB6D6ajCM3WzlXdJVpRs7Ouu3Uw5IeeLpE/bsHOoq+8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744028892; c=relaxed/simple; bh=2o4HproG0lV+6CiJy2e2v2QRjfeRHQV3nL2UwubnNis=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=W4MODK4MXccgmFknRLnfKuBedxFrZiLViUkYYpRS54bHCtzlRfyWJ3d5buf5qsCpdaUdvXPT0BsLoXA9BP0SwX85k4FcZU6PjTuBWZLXw8oJol0iU3Q/FovVkpOR7WrovipEM+U3I2pX0idMgNrfyTOUF0svqNpu06NxV+AJcCA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=H57H6F4J; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="H57H6F4J" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3525FC4CEE7; Mon, 7 Apr 2025 12:28:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744028891; bh=2o4HproG0lV+6CiJy2e2v2QRjfeRHQV3nL2UwubnNis=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H57H6F4JJ5H/IuuJsy3mS27ZfEHXGNxu5o6j3PyHMAsO3NMGyjRLyQYXxvkripA6i p2rc7+G0EWhj3qBCVSzdhndmfqpKlo2NYtIOa9inISnvLWEcnpMByPfjwFnL+BLQS0 Ol9CSZU+Rd9/8w3DCaoe9maNsf9uxxL2EE/BPRTtc6Ohltn2chNvuCMyBH6SRFncHQ UW/YmRCOgF+ZC3K21TYl5XmeJRmv1dR0heyOmyCR4jzUD7SKh+Pyr34rYLBO4FGbH7 FoVdlRURId39Moj+WSWmpMPBTWzp3RrBP5c3xMi568TLiYDPPd/q356PN7O67hpbxl YsjS2pb9ibELw== From: Jarkko Sakkinen To: keyrings@vger.kernel.org Cc: Jarkko Sakkinen , stable@vger.kernel.org, Herbert Xu , David Howells , Lukas Wunner , Ignat Korchagin , "David S. Miller" , Peter Huewe , Jason Gunthorpe , James Bottomley , Ard Biesheuvel , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org Subject: [PATCH v4] tpm: Mask TPM RC in tpm2_start_auth_session() Date: Mon, 7 Apr 2025 15:28:05 +0300 Message-Id: <20250407122806.15400-1-jarkko@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250407072057.81062-1-jarkko@kernel.org> References: <20250407072057.81062-1-jarkko@kernel.org> Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 tpm2_start_auth_session() does not mask TPM RC correctly from the callers: [ 28.766528] tpm tpm0: A TPM error (2307) occurred start auth session Process TPM RCs inside tpm2_start_auth_session(), and map them to POSIX error codes. Cc: stable@vger.kernel.org # v6.10+ Fixes: 699e3efd6c64 ("tpm: Add HMAC session start and end functions") Reported-by: Herbert Xu Closes: https://lore.kernel.org/linux-integrity/Z_NgdRHuTKP6JK--@gondor.apana.org.au/ Signed-off-by: Jarkko Sakkinen Reviewed-by: Stefano Garzarella --- v4: - tpm_to_ret() v3: - rc > 0 v2: - Investigate TPM rc only after destroying tpm_buf. --- drivers/char/tpm/tpm2-sessions.c | 20 ++++++-------------- include/linux/tpm.h | 21 +++++++++++++++++++++ 2 files changed, 27 insertions(+), 14 deletions(-) diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index 3f89635ba5e8..102e099f22c1 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -40,11 +40,6 @@ * * These are the usage functions: * - * tpm2_start_auth_session() which allocates the opaque auth structure - * and gets a session from the TPM. This must be called before - * any of the following functions. The session is protected by a - * session_key which is derived from a random salt value - * encrypted to the NULL seed. * tpm2_end_auth_session() kills the session and frees the resources. * Under normal operation this function is done by * tpm_buf_check_hmac_response(), so this is only to be used on @@ -963,16 +958,13 @@ static int tpm2_load_null(struct tpm_chip *chip, u32 *null_key) } /** - * tpm2_start_auth_session() - create a HMAC authentication session with the TPM - * @chip: the TPM chip structure to create the session with + * tpm2_start_auth_session() - Create an a HMAC authentication session + * @chip: A TPM chip * - * This function loads the NULL seed from its saved context and starts - * an authentication session on the null seed, fills in the - * @chip->auth structure to contain all the session details necessary - * for performing the HMAC, encrypt and decrypt operations and - * returns. The NULL seed is flushed before this function returns. + * Loads the ephemeral key (null seed), and starts an HMAC authenticated + * session. The null seed is flushed before the return. * - * Return: zero on success or actual error encountered. + * Returns zero on success, or a POSIX error code. */ int tpm2_start_auth_session(struct tpm_chip *chip) { @@ -1024,7 +1016,7 @@ int tpm2_start_auth_session(struct tpm_chip *chip) /* hash algorithm for session */ tpm_buf_append_u16(&buf, TPM_ALG_SHA256); - rc = tpm_transmit_cmd(chip, &buf, 0, "start auth session"); + rc = tpm_to_ret(tpm_transmit_cmd(chip, &buf, 0, "StartAuthSession")); tpm2_flush_context(chip, null_key); if (rc == TPM2_RC_SUCCESS) diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 6c3125300c00..c826d5a9d894 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -257,8 +257,29 @@ enum tpm2_return_codes { TPM2_RC_TESTING = 0x090A, /* RC_WARN */ TPM2_RC_REFERENCE_H0 = 0x0910, TPM2_RC_RETRY = 0x0922, + TPM2_RC_SESSION_MEMORY = 0x0903, }; +/* + * Convert a return value from tpm_transmit_cmd() to a POSIX return value. The + * fallback return value is -EFAULT. + */ +static inline ssize_t tpm_to_ret(ssize_t ret) +{ + /* Already a POSIX error: */ + if (ret < 0) + return ret; + + switch (ret) { + case TPM2_RC_SUCCESS: + return 0; + case TPM2_RC_SESSION_MEMORY: + return -ENOMEM; + default: + return -EFAULT; + } +} + enum tpm2_command_codes { TPM2_CC_FIRST = 0x011F, TPM2_CC_HIERARCHY_CONTROL = 0x0121,