From nobody Wed Oct 1 23:30:10 2025 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 C871621B9C0; Mon, 29 Sep 2025 03:59:54 +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=1759118394; cv=none; b=B17bIaI/STf5X+9m5K45unnuORlJDicQJ4J0Ejnc2uffWMhqGjKjCX8nwSwskemL0KU38hi11+wN9l+CB21XlPmZiQt0FRXcqZMGSNd8tQg/ak4pr431pDtss4n4tJl2yKZZzb3f4OrreEgKQEj+048aITF7idr/fSc02sbej8w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759118394; c=relaxed/simple; bh=q1gt730fnSd2Av052hqSCVRgXrypYYybsDg0l/9rpQE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=oX2GToslwSj4L+7WzgkUpXAR3GrH8gLzqNV6DuMsxY9PENXdBHCH6rnaVoOa5qYWsOuoE+NeYgFsN0YSL6Tx/VWrEEaNXKINtnBJznz08fxYUP7KEPTLGmEnQc4GX1FwFnntFMwIqvmiVP+a7xym8kflwD1c/P+KtnNtOrAeiRw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Yh96lChb; 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="Yh96lChb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9DB4C116B1; Mon, 29 Sep 2025 03:59:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1759118394; bh=q1gt730fnSd2Av052hqSCVRgXrypYYybsDg0l/9rpQE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Yh96lChbM7jTHNlV+UNRzkrbovHmEroZXnrFTnWUwVPiQ1wYg4d0Y4CKx2rFqCkCm rXvO1Ka+2vIa29zccfBW1LkgXvtIsY8Iec5OALafd9NmouZZ2on8lANhx/LRD3tDgE TzPKSt2AjLw0RDHYeZmD0YIgI6U36j7rs99dvX+FSpQHYAr/V6v3ADXTph2E4PobqV ZCh5l3e6X36Rqewe9oANgCxWVrJzlo7D6T3J15HZlAxque7iOLdS6jzH0Rv25ktbOv J0Uu97Kcg6hcl+PODzw0FrfGrefYf2Zkppwou46aBdRJS6/vs0VVzJ682HlGlpW5Hk A13ukCe6s+6IA== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org Cc: dpsmith@apertussolutions.com, ross.philipson@oracle.com, Jarkko Sakkinen , Roberto Sassu , Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe , David Howells , Paul Moore , James Morris , "Serge E. Hallyn" , linux-kernel@vger.kernel.org (open list), keyrings@vger.kernel.org (open list:KEYS/KEYRINGS), linux-security-module@vger.kernel.org (open list:SECURITY SUBSYSTEM) Subject: [PATCH v2 1/9] tpm: cap PCR bank in tpm2_get_pcr_allocations() Date: Mon, 29 Sep 2025 06:59:30 +0300 Message-Id: <20250929035938.1773341-2-jarkko@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250929035938.1773341-1-jarkko@kernel.org> References: <20250929035938.1773341-1-jarkko@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Jarkko Sakkinen tpm2_get_pcr_allocation() does not cap any upper limit for the number of banks received from external hardware device. This could lead into resource over-consumption with a fauly TPM device. Cc: Roberto Sassu Fixes: bcfff8384f6c ("tpm: dynamically allocate the allocated_banks array") Signed-off-by: Jarkko Sakkinen --- v2: - A new patch. --- drivers/char/tpm/tpm-chip.c | 13 +++++++++---- drivers/char/tpm/tpm.h | 1 - drivers/char/tpm/tpm1-cmd.c | 25 ------------------------- drivers/char/tpm/tpm2-cmd.c | 8 +++----- include/linux/tpm.h | 18 ++++++++---------- 5 files changed, 20 insertions(+), 45 deletions(-) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 687f6d8cd601..9a6538f76f50 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -559,14 +559,19 @@ static int tpm_add_hwrng(struct tpm_chip *chip) =20 static int tpm_get_pcr_allocation(struct tpm_chip *chip) { - int rc; + int rc =3D 0; =20 if (tpm_is_firmware_upgrade(chip)) return 0; =20 - rc =3D (chip->flags & TPM_CHIP_FLAG_TPM2) ? - tpm2_get_pcr_allocation(chip) : - tpm1_get_pcr_allocation(chip); + if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { + chip->allocated_banks[0].alg_id =3D TPM_ALG_SHA1; + chip->allocated_banks[0].digest_size =3D hash_digest_size[HASH_ALGO_SHA1= ]; + chip->allocated_banks[0].crypto_id =3D HASH_ALGO_SHA1; + chip->nr_allocated_banks =3D 1; + } else { + rc =3D tpm2_get_pcr_allocation(chip); + } =20 if (rc > 0) return -ENODEV; diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 57ef8589f5f5..769fa6b00c54 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -252,7 +252,6 @@ int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u= 8 *res_buf); ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap, const char *desc, size_t min_cap_length); int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max); -int tpm1_get_pcr_allocation(struct tpm_chip *chip); unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal= ); int tpm_pm_suspend(struct device *dev); int tpm_pm_resume(struct device *dev); diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c index cf64c7385105..5c49bdff33de 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -786,28 +786,3 @@ int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_sus= pend_pcr) =20 return rc; } - -/** - * tpm1_get_pcr_allocation() - initialize the allocated bank - * @chip: TPM chip to use. - * - * The function initializes the SHA1 allocated bank to extend PCR - * - * Return: - * * 0 on success, - * * < 0 on error. - */ -int tpm1_get_pcr_allocation(struct tpm_chip *chip) -{ - chip->allocated_banks =3D kcalloc(1, sizeof(*chip->allocated_banks), - GFP_KERNEL); - if (!chip->allocated_banks) - return -ENOMEM; - - chip->allocated_banks[0].alg_id =3D TPM_ALG_SHA1; - chip->allocated_banks[0].digest_size =3D hash_digest_size[HASH_ALGO_SHA1]; - chip->allocated_banks[0].crypto_id =3D HASH_ALGO_SHA1; - chip->nr_allocated_banks =3D 1; - - return 0; -} diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 7d77f6fbc152..e416cc8705e3 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -538,11 +538,9 @@ ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) =20 nr_possible_banks =3D be32_to_cpup( (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]); - - chip->allocated_banks =3D kcalloc(nr_possible_banks, - sizeof(*chip->allocated_banks), - GFP_KERNEL); - if (!chip->allocated_banks) { + if (nr_possible_banks > TPM2_MAX_BANKS) { + pr_err("tpm:: unexpected large number of banks: %u > %u", + nr_possible_banks, TPM2_MAX_BANKS); rc =3D -ENOMEM; goto out; } diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 900c81a2bc41..fc7df87dfb9a 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -27,7 +27,12 @@ #include =20 #define TPM_DIGEST_SIZE 20 /* Max TPM v1.2 PCR size */ -#define TPM_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE +#define TPM_HEADER_SIZE 10 + +#define TPM2_PLATFORM_PCR 24 +#define TPM2_PCR_SELECT_MIN 3 +#define TPM2_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE +#define TPM2_MAX_BANKS 4 =20 struct tpm_chip; struct trusted_key_payload; @@ -69,7 +74,7 @@ enum tpm2_curves { =20 struct tpm_digest { u16 alg_id; - u8 digest[TPM_MAX_DIGEST_SIZE]; + u8 digest[TPM2_MAX_DIGEST_SIZE]; } __packed; =20 struct tpm_bank_info { @@ -190,7 +195,7 @@ struct tpm_chip { unsigned int groups_cnt; =20 u32 nr_allocated_banks; - struct tpm_bank_info *allocated_banks; + struct tpm_bank_info allocated_banks[TPM2_MAX_BANKS]; #ifdef CONFIG_ACPI acpi_handle acpi_dev_handle; char ppi_version[TPM_PPI_VERSION_LEN + 1]; @@ -217,13 +222,6 @@ struct tpm_chip { #endif }; =20 -#define TPM_HEADER_SIZE 10 - -enum tpm2_const { - TPM2_PLATFORM_PCR =3D 24, - TPM2_PCR_SELECT_MIN =3D ((TPM2_PLATFORM_PCR + 7) / 8), -}; - enum tpm2_timeouts { TPM2_TIMEOUT_A =3D 750, TPM2_TIMEOUT_B =3D 4000, --=20 2.39.5