From mboxrd@z Thu Jan 1 00:00:00 1970 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 B6C36F9D9; Wed, 14 Jan 2026 17:23:30 +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=1768411410; cv=none; b=YsZGPLllDZTtw4quVRAcqeb8kMsY+WxMr/1zJg61d8FBlHMFe/DqanQgKaVsoBWqnTuOXtYLrS5ZDdIM+kh2iY+0ogfXxJUjysEkOe8CoNCrGcUzgJaj5rDRyjK6TWAERKN8dt/FCse2zxJ9RTowcMU1i9hRimy9o6uWJLuAMlc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768411410; c=relaxed/simple; bh=0OoRY2fr0e9jkZJlre5dLw723/9l5nxBj7cT3jVFMDw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=cUL8mgXhacVyF96BJ9vHBLgJBYTLb6JAvA12/FxfnLYbb2wK8Pb22Tbu8rfhJOzskF8eV72FFOcARbFwgkys4CAx9wDMEQnAqtk0XEkdjgn4g55fuCFxJh4IHVzV1mX41h1oueBgDX9KXUAXEW48M34WDd/WAfbk7w5rXYhkd8A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IjcruE4L; 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="IjcruE4L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B266AC19421; Wed, 14 Jan 2026 17:23:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768411410; bh=0OoRY2fr0e9jkZJlre5dLw723/9l5nxBj7cT3jVFMDw=; h=From:To:Cc:Subject:Date:From; b=IjcruE4L2/E11RWzeVv9d2+Mh9ZaSNWdrAwLaIwlx2HiB5135uyR6QdO1TGImMQwj 8ZHFmlkyc3uQExUeCrZD1iDc2SsdHWbvlNK7qqVjL4ESvhpHtEDtvJm1jujtPsWuiP MIqmlaKU8zMDBDEPI94YdF48I/J95rkBehj05pkCmqrqc47EzzPznFbta3xpZkhbDW EI6+9wh9QEIDmFCrqmHvXE4sN994Z4TPFxygW5mT7E6Xbk1p7cYRNy+5putrzqTJpl rQ0HGbx4QGeZEn/cUoWGENUUfwb66HwnvYsrv9/1KkFWVh2Vr+7XBg/xGtykCSsZ0e ejBF5bt8iIFTg== From: Jarkko Sakkinen To: stable@vger.kernel.org Cc: linux-integrity@vger.kernel.org, Jarkko Sakkinen , Jonathan McDowell Subject: [PATCH v2] tpm2-sessions: Fix out of range indexing in name_size Date: Wed, 14 Jan 2026 19:23:22 +0200 Message-ID: <20260114172322.800027-1-jarkko@kernel.org> X-Mailer: git-send-email 2.52.0 Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit [ Upstream commit 6e9722e9a7bfe1bbad649937c811076acf86e1fd ] 'name_size' does not have any range checks, and it just directly indexes with TPM_ALG_ID, which could lead into memory corruption at worst. Address the issue by only processing known values and returning -EINVAL for unrecognized values. Make also 'tpm_buf_append_name' and 'tpm_buf_fill_hmac_session' fallible so that errors are detected before causing any spurious TPM traffic. End also the authorization session on failure in both of the functions, as the session state would be then by definition corrupted. Cc: stable@vger.kernel.org # v6.10+ Fixes: 1085b8276bb4 ("tpm: Add the rest of the session HMAC API") Reviewed-by: Jonathan McDowell Signed-off-by: Jarkko Sakkinen --- Backport for v6.12. --- drivers/char/tpm/tpm2-cmd.c | 23 ++++- drivers/char/tpm/tpm2-sessions.c | 114 ++++++++++++++-------- include/linux/tpm.h | 13 ++- security/keys/trusted-keys/trusted_tpm2.c | 29 ++++-- 4 files changed, 126 insertions(+), 53 deletions(-) diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index b58a8a7e1564..d7aabb66a4d1 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -253,7 +253,11 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, } if (!disable_pcr_integrity) { - tpm_buf_append_name(chip, &buf, pcr_idx, NULL); + rc = tpm_buf_append_name(chip, &buf, pcr_idx, NULL); + if (rc) { + tpm_buf_destroy(&buf); + return rc; + } tpm_buf_append_hmac_session(chip, &buf, 0, NULL, 0); } else { tpm_buf_append_handle(chip, &buf, pcr_idx); @@ -268,8 +272,14 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, chip->allocated_banks[i].digest_size); } - if (!disable_pcr_integrity) - tpm_buf_fill_hmac_session(chip, &buf); + if (!disable_pcr_integrity) { + rc = tpm_buf_fill_hmac_session(chip, &buf); + if (rc) { + tpm_buf_destroy(&buf); + return rc; + } + } + rc = tpm_transmit_cmd(chip, &buf, 0, "attempting extend a PCR value"); if (!disable_pcr_integrity) rc = tpm_buf_check_hmac_response(chip, &buf, rc); @@ -327,7 +337,12 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) | TPM2_SA_CONTINUE_SESSION, NULL, 0); tpm_buf_append_u16(&buf, num_bytes); - tpm_buf_fill_hmac_session(chip, &buf); + err = tpm_buf_fill_hmac_session(chip, &buf); + if (err) { + tpm_buf_destroy(&buf); + return err; + } + err = tpm_transmit_cmd(chip, &buf, offsetof(struct tpm2_get_random_out, buffer), diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index a10db4a4aced..4d9acfb1787e 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -144,16 +144,23 @@ struct tpm2_auth { /* * Name Size based on TPM algorithm (assumes no hash bigger than 255) */ -static u8 name_size(const u8 *name) +static int name_size(const u8 *name) { - static u8 size_map[] = { - [TPM_ALG_SHA1] = SHA1_DIGEST_SIZE, - [TPM_ALG_SHA256] = SHA256_DIGEST_SIZE, - [TPM_ALG_SHA384] = SHA384_DIGEST_SIZE, - [TPM_ALG_SHA512] = SHA512_DIGEST_SIZE, - }; - u16 alg = get_unaligned_be16(name); - return size_map[alg] + 2; + u16 hash_alg = get_unaligned_be16(name); + + switch (hash_alg) { + case TPM_ALG_SHA1: + return SHA1_DIGEST_SIZE + 2; + case TPM_ALG_SHA256: + return SHA256_DIGEST_SIZE + 2; + case TPM_ALG_SHA384: + return SHA384_DIGEST_SIZE + 2; + case TPM_ALG_SHA512: + return SHA512_DIGEST_SIZE + 2; + default: + pr_warn("tpm: unsupported name algorithm: 0x%04x\n", hash_alg); + return -EINVAL; + } } static int tpm2_read_public(struct tpm_chip *chip, u32 handle, void *name) @@ -234,9 +241,11 @@ static int tpm2_read_public(struct tpm_chip *chip, u32 handle, void *name) * As with most tpm_buf operations, success is assumed because failure * will be caused by an incorrect programming model and indicated by a * kernel message. + * + * Ends the authorization session on failure. */ -void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, - u32 handle, u8 *name) +int tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, + u32 handle, u8 *name) { #ifdef CONFIG_TCG_TPM2_HMAC enum tpm2_mso_type mso = tpm2_handle_mso(handle); @@ -247,18 +256,22 @@ void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, if (!tpm2_chip_auth(chip)) { tpm_buf_append_handle(chip, buf, handle); - return; + return 0; } #ifdef CONFIG_TCG_TPM2_HMAC slot = (tpm_buf_length(buf) - TPM_HEADER_SIZE) / 4; if (slot >= AUTH_MAX_NAMES) { - dev_err(&chip->dev, "TPM: too many handles\n"); - return; + dev_err(&chip->dev, "too many handles\n"); + ret = -EIO; + goto err; } auth = chip->auth; - WARN(auth->session != tpm_buf_length(buf), - "name added in wrong place\n"); + if (auth->session != tpm_buf_length(buf)) { + dev_err(&chip->dev, "session state malformed"); + ret = -EIO; + goto err; + } tpm_buf_append_u32(buf, handle); auth->session += 4; @@ -271,17 +284,29 @@ void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, goto err; } } else { - if (name) - dev_err(&chip->dev, "TPM: Handle does not require name but one is specified\n"); + if (name) { + dev_err(&chip->dev, "handle 0x%08x does not use a name\n", + handle); + ret = -EIO; + goto err; + } } auth->name_h[slot] = handle; - if (name) - memcpy(auth->name[slot], name, name_size(name)); - return; + if (name) { + ret = name_size(name); + if (ret < 0) + goto err; + + memcpy(auth->name[slot], name, ret); + } +#endif + return 0; +#ifdef CONFIG_TCG_TPM2_HMAC err: tpm2_end_auth_session(chip); + return tpm_ret_to_err(ret); #endif } EXPORT_SYMBOL_GPL(tpm_buf_append_name); @@ -599,11 +624,9 @@ static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip, * encryption key and encrypts the first parameter of the command * buffer with it. * - * As with most tpm_buf operations, success is assumed because failure - * will be caused by an incorrect programming model and indicated by a - * kernel message. + * Ends the authorization session on failure. */ -void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) +int tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) { u32 cc, handles, val; struct tpm2_auth *auth = chip->auth; @@ -614,9 +637,12 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) u32 attrs; u8 cphash[SHA256_DIGEST_SIZE]; struct sha256_state sctx; + int ret; - if (!auth) - return; + if (!auth) { + ret = -EIO; + goto err; + } /* save the command code in BE format */ auth->ordinal = head->ordinal; @@ -625,9 +651,11 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) i = tpm2_find_cc(chip, cc); if (i < 0) { - dev_err(&chip->dev, "Command 0x%x not found in TPM\n", cc); - return; + dev_err(&chip->dev, "command 0x%08x not found\n", cc); + ret = -EIO; + goto err; } + attrs = chip->cc_attrs_tbl[i]; handles = (attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0); @@ -641,9 +669,9 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) u32 handle = tpm_buf_read_u32(buf, &offset_s); if (auth->name_h[i] != handle) { - dev_err(&chip->dev, "TPM: handle %d wrong for name\n", - i); - return; + dev_err(&chip->dev, "invalid handle 0x%08x\n", handle); + ret = -EIO; + goto err; } } /* point offset_s to the start of the sessions */ @@ -674,12 +702,14 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) offset_s += len; } if (offset_s != offset_p) { - dev_err(&chip->dev, "TPM session length is incorrect\n"); - return; + dev_err(&chip->dev, "session length is incorrect\n"); + ret = -EIO; + goto err; } if (!hmac) { - dev_err(&chip->dev, "TPM could not find HMAC session\n"); - return; + dev_err(&chip->dev, "could not find HMAC session\n"); + ret = -EIO; + goto err; } /* encrypt before HMAC */ @@ -711,8 +741,11 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) if (mso == TPM2_MSO_PERSISTENT || mso == TPM2_MSO_VOLATILE || mso == TPM2_MSO_NVRAM) { - sha256_update(&sctx, auth->name[i], - name_size(auth->name[i])); + ret = name_size(auth->name[i]); + if (ret < 0) + goto err; + + sha256_update(&sctx, auth->name[i], ret); } else { __be32 h = cpu_to_be32(auth->name_h[i]); @@ -733,6 +766,11 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) sha256_update(&sctx, &auth->attrs, 1); tpm2_hmac_final(&sctx, auth->session_key, sizeof(auth->session_key) + auth->passphrase_len, hmac); + return 0; + +err: + tpm2_end_auth_session(chip); + return ret; } EXPORT_SYMBOL(tpm_buf_fill_hmac_session); diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 117e0f620d52..4d2b6de85d47 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -523,8 +523,8 @@ static inline struct tpm2_auth *tpm2_chip_auth(struct tpm_chip *chip) #endif } -void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, - u32 handle, u8 *name); +int tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, + u32 handle, u8 *name); void tpm_buf_append_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf, u8 attributes, u8 *passphrase, int passphraselen); @@ -557,7 +557,7 @@ static inline void tpm_buf_append_hmac_session_opt(struct tpm_chip *chip, #ifdef CONFIG_TCG_TPM2_HMAC int tpm2_start_auth_session(struct tpm_chip *chip); -void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf); +int tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf); int tpm_buf_check_hmac_response(struct tpm_chip *chip, struct tpm_buf *buf, int rc); void tpm2_end_auth_session(struct tpm_chip *chip); @@ -571,10 +571,13 @@ static inline int tpm2_start_auth_session(struct tpm_chip *chip) static inline void tpm2_end_auth_session(struct tpm_chip *chip) { } -static inline void tpm_buf_fill_hmac_session(struct tpm_chip *chip, - struct tpm_buf *buf) + +static inline int tpm_buf_fill_hmac_session(struct tpm_chip *chip, + struct tpm_buf *buf) { + return 0; } + static inline int tpm_buf_check_hmac_response(struct tpm_chip *chip, struct tpm_buf *buf, int rc) diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index 76a86f8a8d6c..7187768716b7 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -283,7 +283,10 @@ int tpm2_seal_trusted(struct tpm_chip *chip, goto out_put; } - tpm_buf_append_name(chip, &buf, options->keyhandle, NULL); + rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL); + if (rc) + goto out; + tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_DECRYPT, options->keyauth, TPM_DIGEST_SIZE); @@ -331,7 +334,10 @@ int tpm2_seal_trusted(struct tpm_chip *chip, goto out; } - tpm_buf_fill_hmac_session(chip, &buf); + rc = tpm_buf_fill_hmac_session(chip, &buf); + if (rc) + goto out; + rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data"); rc = tpm_buf_check_hmac_response(chip, &buf, rc); if (rc) @@ -448,7 +454,10 @@ static int tpm2_load_cmd(struct tpm_chip *chip, return rc; } - tpm_buf_append_name(chip, &buf, options->keyhandle, NULL); + rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL); + if (rc) + goto out; + tpm_buf_append_hmac_session(chip, &buf, 0, options->keyauth, TPM_DIGEST_SIZE); @@ -460,7 +469,10 @@ static int tpm2_load_cmd(struct tpm_chip *chip, goto out; } - tpm_buf_fill_hmac_session(chip, &buf); + rc = tpm_buf_fill_hmac_session(chip, &buf); + if (rc) + goto out; + rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob"); rc = tpm_buf_check_hmac_response(chip, &buf, rc); if (!rc) @@ -508,7 +520,9 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, return rc; } - tpm_buf_append_name(chip, &buf, blob_handle, NULL); + rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL); + if (rc) + goto out; if (!options->policyhandle) { tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_ENCRYPT, @@ -533,7 +547,10 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, NULL, 0); } - tpm_buf_fill_hmac_session(chip, &buf); + rc = tpm_buf_fill_hmac_session(chip, &buf); + if (rc) + goto out; + rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing"); rc = tpm_buf_check_hmac_response(chip, &buf, rc); if (rc > 0) -- 2.52.0