From patchwork Mon Nov 27 19:08:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13470192 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="oVieHh/h" Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [IPv6:2607:fcd0:100:8a00::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C428AD5D; Mon, 27 Nov 2023 11:10:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1701112244; bh=kMqkyTh5dfFvi5X3GaY8p34QwAHzovDkXGb6zpN87Co=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=oVieHh/hz7A3SWWqwQ2496ayvyYo02DH0NtxzpL8Gql+OG/l8A97GGK1onEUi4w2x eoDvvdp0oAykiWlfd4XdGmy4WjL9qDfbv84F4gmlezA2/V3BSPRFYiZ0i1xklEUxSv ZG32J6XUQjhO+Wp/w9bduRn0OEd2qYWQGrKb5FtQ= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 95E5F128174C; Mon, 27 Nov 2023 14:10:44 -0500 (EST) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id 8loXcxCUaeE9; Mon, 27 Nov 2023 14:10:44 -0500 (EST) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 058C61280087; Mon, 27 Nov 2023 14:10:43 -0500 (EST) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v5 05/17] tpm: Store the length of the tpm_buf data separately. Date: Mon, 27 Nov 2023 14:08:42 -0500 Message-Id: <20231127190854.13310-6-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20231127190854.13310-1-James.Bottomley@HansenPartnership.com> References: <20231127190854.13310-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Jarkko Sakkinen TPM2B buffers, or sized buffers, have a two byte header, which contains the length of the payload as a 16-bit big-endian number, without counting in the space taken by the header. This differs from encoding in the TPM header where the length includes also the bytes taken by the header. Unbound the length of a tpm_buf from the value stored to the TPM command header. A separate encoding and decoding step so that different buffer types can be supported, with variant header format and length encoding. Signed-off-by: Jarkko Sakkinen Signed-off-by: James Bottomley --- drivers/char/tpm/tpm-buf.c | 48 +++++++++++++++++------ drivers/char/tpm/tpm-interface.c | 1 + include/keys/trusted_tpm.h | 2 - include/linux/tpm.h | 6 +-- security/keys/trusted-keys/trusted_tpm1.c | 9 +++-- 5 files changed, 46 insertions(+), 20 deletions(-) diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c index 96cee41d5b9c..3f39893f3bb1 100644 --- a/drivers/char/tpm/tpm-buf.c +++ b/drivers/char/tpm/tpm-buf.c @@ -3,25 +3,44 @@ * Handling of TPM command and other buffers. */ +#include #include #include +/** + * tpm_buf_init() - Allocate and initialize a TPM command + * @buf: A &tpm_buf + * @tag: TPM_TAG_RQU_COMMAND, TPM2_ST_NO_SESSIONS or TPM2_ST_SESSIONS + * @ordinal: A command ordinal + * + * Return: 0 or -ENOMEM + */ int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal) { buf->data = (u8 *)__get_free_page(GFP_KERNEL); if (!buf->data) return -ENOMEM; - buf->flags = 0; tpm_buf_reset(buf, tag, ordinal); return 0; } EXPORT_SYMBOL_GPL(tpm_buf_init); +/** + * tpm_buf_reset() - Initialize a TPM command + * @buf: A &tpm_buf + * @tag: TPM_TAG_RQU_COMMAND, TPM2_ST_NO_SESSIONS or TPM2_ST_SESSIONS + * @ordinal: A command ordinal + */ void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal) { struct tpm_header *head = (struct tpm_header *)buf->data; + WARN_ON(tag != TPM_TAG_RQU_COMMAND && tag != TPM2_ST_NO_SESSIONS && + tag != TPM2_ST_SESSIONS && tag != 0); + + buf->flags = 0; + buf->length = sizeof(*head); head->tag = cpu_to_be16(tag); head->length = cpu_to_be32(sizeof(*head)); head->ordinal = cpu_to_be32(ordinal); @@ -34,33 +53,40 @@ void tpm_buf_destroy(struct tpm_buf *buf) } EXPORT_SYMBOL_GPL(tpm_buf_destroy); +/** + * tpm_buf_length() - Return the number of bytes consumed by the data + * + * Return: The number of bytes consumed by the buffer + */ u32 tpm_buf_length(struct tpm_buf *buf) { - struct tpm_header *head = (struct tpm_header *)buf->data; - - return be32_to_cpu(head->length); + return buf->length; } EXPORT_SYMBOL_GPL(tpm_buf_length); -void tpm_buf_append(struct tpm_buf *buf, - const unsigned char *new_data, - unsigned int new_len) +/** + * tpm_buf_append() - Append data to an initialized buffer + * @buf: A &tpm_buf + * @new_data: A data blob + * @new_length: Size of the appended data + */ +void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length) { struct tpm_header *head = (struct tpm_header *)buf->data; - u32 len = tpm_buf_length(buf); /* Return silently if overflow has already happened. */ if (buf->flags & TPM_BUF_OVERFLOW) return; - if ((len + new_len) > PAGE_SIZE) { + if ((buf->length + new_length) > PAGE_SIZE) { WARN(1, "tpm_buf: overflow\n"); buf->flags |= TPM_BUF_OVERFLOW; return; } - memcpy(&buf->data[len], new_data, new_len); - head->length = cpu_to_be32(len + new_len); + memcpy(&buf->data[buf->length], new_data, new_length); + buf->length += new_length; + head->length = cpu_to_be32(buf->length); } EXPORT_SYMBOL_GPL(tpm_buf_append); diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 163ae247bff2..ea75f2776c2f 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -232,6 +232,7 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf, if (len < min_rsp_body_length + TPM_HEADER_SIZE) return -EFAULT; + buf->length = len; return 0; } EXPORT_SYMBOL_GPL(tpm_transmit_cmd); diff --git a/include/keys/trusted_tpm.h b/include/keys/trusted_tpm.h index 7769b726863a..a088b33fd0e3 100644 --- a/include/keys/trusted_tpm.h +++ b/include/keys/trusted_tpm.h @@ -6,8 +6,6 @@ #include /* implementation specific TPM constants */ -#define MAX_BUF_SIZE 1024 -#define TPM_GETRANDOM_SIZE 14 #define TPM_SIZE_OFFSET 2 #define TPM_RETURN_OFFSET 6 #define TPM_DATA_OFFSET 10 diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 0a8c1351adc2..1d7b39b5c383 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -306,7 +306,8 @@ enum tpm_buf_flags { * A string buffer type for constructing TPM commands. */ struct tpm_buf { - unsigned int flags; + u32 flags; + u32 length; u8 *data; }; @@ -329,8 +330,7 @@ int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal); void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal); void tpm_buf_destroy(struct tpm_buf *buf); u32 tpm_buf_length(struct tpm_buf *buf); -void tpm_buf_append(struct tpm_buf *buf, const unsigned char *new_data, - unsigned int new_len); +void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length); void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value); void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value); void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value); diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index 37bce84eef99..89c9798d1800 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -367,6 +367,7 @@ int trusted_tpm_send(unsigned char *cmd, size_t buflen) return rc; buf.flags = 0; + buf.length = buflen; buf.data = cmd; dump_tpm_buf(cmd); rc = tpm_transmit_cmd(chip, &buf, 4, "sending data"); @@ -417,7 +418,7 @@ static int osap(struct tpm_buf *tb, struct osapsess *s, tpm_buf_append_u32(tb, handle); tpm_buf_append(tb, ononce, TPM_NONCE_SIZE); - ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + ret = trusted_tpm_send(tb->data, tb->length); if (ret < 0) return ret; @@ -441,7 +442,7 @@ int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce) return -ENODEV; tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP); - ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + ret = trusted_tpm_send(tb->data, tb->length); if (ret < 0) return ret; @@ -553,7 +554,7 @@ static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, tpm_buf_append_u8(tb, cont); tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE); - ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + ret = trusted_tpm_send(tb->data, tb->length); if (ret < 0) goto out; @@ -644,7 +645,7 @@ static int tpm_unseal(struct tpm_buf *tb, tpm_buf_append_u8(tb, cont); tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE); - ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + ret = trusted_tpm_send(tb->data, tb->length); if (ret < 0) { pr_info("authhmac failed (%d)\n", ret); return ret;