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 8129229BD95 for ; Thu, 8 Jan 2026 17:17:04 +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=1767892624; cv=none; b=gnGLNlayBqKfLvmIT/Xll+w9vWEU73rhTmAo+XD9+EJulI4Re9+PYJydRZ/uAqvsoIQL1wJt+b2wkHOOxUPcxwb3LDI7shyLZ9cZc0HEfrkMF1ZafUOmEK3ohNA5FzP0wawZFMsfv4t+v7G4nG/EKqkPgejYkstIGO0kqB7FKAQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767892624; c=relaxed/simple; bh=6vq0SXBRUS62FP3sy2JE5TxatsPmBg3OXFU7384/lfo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZbQ/awcmuRw3pOo+k3mmPXMI3y+bsEG4kRvFX9wowOdH0N3YZb7S42E0CFYmcn6cQ7OktvbsGNuUd9FKwShvBIjveM1zuP25EMTanaKbzvDXEJunxgZA9XqmU6CjSCmg8pB6C7sPLVGYjE02aaK7trzRDSG5ieAandRgflH3CB4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=C9oCBfUp; 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="C9oCBfUp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5821C116D0; Thu, 8 Jan 2026 17:17:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767892624; bh=6vq0SXBRUS62FP3sy2JE5TxatsPmBg3OXFU7384/lfo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C9oCBfUpk/PAHhE8fPc4/dCQW89YevTkNax4FzcxYbgPbTZ1MuQnIy8LuEWLTE7Kh 9laL7Is2qfSkBnG9JFnE/vT0KnI/GLRdYihMNLUmVBlLQT3OT3KGHr5EB+tv37xlna MTxJNnQfkh7EBAoFi3uaZ1FvyaXAxf26GLRcN4wwsJMZEFudD5zaSQSMTwo7OE7bCm TlrvgpX4WaeWWuA7ZfXQ735Gz7SFsoPtTPttXXHAFs6MLo4y+ieVVLDBWFMys7JFn5 WKZ4ro0WZnaPREQoHiTRX0sp4vEevrFJtS36uEGk7nPT9kxFl6HTrGQtLmuZ5rmVZX ZY3Rn9BZ9IWVw== From: Sasha Levin To: stable@vger.kernel.org Cc: Jarkko Sakkinen , Lai Yi , Jonathan McDowell , Roberto Sassu , Sasha Levin Subject: [PATCH 5.15.y] tpm: Cap the number of PCR banks Date: Thu, 8 Jan 2026 12:17:00 -0500 Message-ID: <20260108171700.1555668-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2026010816-security-maimed-0bb1@gregkh> References: <2026010816-security-maimed-0bb1@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Jarkko Sakkinen [ Upstream commit faf07e611dfa464b201223a7253e9dc5ee0f3c9e ] tpm2_get_pcr_allocation() does not cap any upper limit for the number of banks. Cap the limit to eight banks so that out of bounds values coming from external I/O cause on only limited harm. Cc: stable@vger.kernel.org # v5.10+ Fixes: bcfff8384f6c ("tpm: dynamically allocate the allocated_banks array") Tested-by: Lai Yi Reviewed-by: Jonathan McDowell Reviewed-by: Roberto Sassu Signed-off-by: Jarkko Sakkinen [ add TPM_MAX_DIGEST_SIZE for backward compatibility and remove CONFIG_TCG_TPM2_HMAC block ] Signed-off-by: Sasha Levin --- drivers/char/tpm/tpm-chip.c | 1 - drivers/char/tpm/tpm1-cmd.c | 5 ----- drivers/char/tpm/tpm2-cmd.c | 8 +++----- include/linux/tpm.h | 9 ++++++--- 4 files changed, 9 insertions(+), 14 deletions(-) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index a3459238ecb3..be9f9a003ce2 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -269,7 +269,6 @@ static void tpm_dev_release(struct device *dev) kfree(chip->work_space.context_buf); kfree(chip->work_space.session_buf); - kfree(chip->allocated_banks); kfree(chip); } diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c index f7dc986fa4a0..0f1754a328cf 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -794,11 +794,6 @@ int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_suspend_pcr) */ int tpm1_get_pcr_allocation(struct tpm_chip *chip) { - chip->allocated_banks = kcalloc(1, sizeof(*chip->allocated_banks), - GFP_KERNEL); - if (!chip->allocated_banks) - return -ENOMEM; - chip->allocated_banks[0].alg_id = TPM_ALG_SHA1; chip->allocated_banks[0].digest_size = hash_digest_size[HASH_ALGO_SHA1]; chip->allocated_banks[0].crypto_id = HASH_ALGO_SHA1; diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index de92065394be..440b703e29e5 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -574,11 +574,9 @@ ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) nr_possible_banks = be32_to_cpup( (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]); - - chip->allocated_banks = kcalloc(nr_possible_banks, - sizeof(*chip->allocated_banks), - GFP_KERNEL); - if (!chip->allocated_banks) { + if (nr_possible_banks > TPM2_MAX_PCR_BANKS) { + pr_err("tpm: out of bank capacity: %u > %u\n", + nr_possible_banks, TPM2_MAX_PCR_BANKS); rc = -ENOMEM; goto out; } diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 2652de93e97b..28f2a31d7c98 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -25,7 +25,10 @@ #include #define TPM_DIGEST_SIZE 20 /* Max TPM v1.2 PCR size */ -#define TPM_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE + +#define TPM2_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE +#define TPM_MAX_DIGEST_SIZE TPM2_MAX_DIGEST_SIZE +#define TPM2_MAX_PCR_BANKS 8 struct tpm_chip; struct trusted_key_payload; @@ -51,7 +54,7 @@ enum tpm_algorithms { struct tpm_digest { u16 alg_id; - u8 digest[TPM_MAX_DIGEST_SIZE]; + u8 digest[TPM2_MAX_DIGEST_SIZE]; } __packed; struct tpm_bank_info { @@ -157,7 +160,7 @@ struct tpm_chip { unsigned int groups_cnt; u32 nr_allocated_banks; - struct tpm_bank_info *allocated_banks; + struct tpm_bank_info allocated_banks[TPM2_MAX_PCR_BANKS]; #ifdef CONFIG_ACPI acpi_handle acpi_dev_handle; char ppi_version[TPM_PPI_VERSION_LEN + 1]; -- 2.51.0