From nobody Wed Oct 1 22:30:45 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 2418E1A2C0B; Tue, 30 Sep 2025 23:20:10 +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=1759274410; cv=none; b=Gq2hdDSWQ+vPaKWFy5nXXgiHELlbIZuNGeuC7oGXGBLDz/1qQcqU7lndbD3eiiU7Lj2djXKk5Ba2ntV3qLrEqchn5eUjOpL8Vw190AqJ6817imkMyIQkuY9J1iUh10gs/YuHlKejuoiIr0oSuD7kVmW9r/5fRMT8nGlnf4UkcJ8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759274410; c=relaxed/simple; bh=jLukbEi9WeHZ/RUrynJjtKIC1cl16Ls2i2TcnnAUgaA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Xv9BG5BVuwQfh2WOw3kopPb6PkrvE46hclOGYwVKZDzN9zjy0qZovd0/Lzj/Le0O1XVvFvbz75LDpCpBDdHEv4RX8KIYyc6hz97NI403DJ/JiCXGfmvkGiNRJ8/7TSOtGgU0Fzo49PdsIKp4qiV3FLmtliKKA2gELM/lFdLBCO0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GSZd6aGz; 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="GSZd6aGz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97764C4CEF0; Tue, 30 Sep 2025 23:20:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1759274410; bh=jLukbEi9WeHZ/RUrynJjtKIC1cl16Ls2i2TcnnAUgaA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GSZd6aGzNV28LNcyZyp1qE/cREWMb4X4VsU4lgktKiWg4SYONQFgMcvVbkYB20V+s vsJq4zqkb01ZU/aykP48kYoLyKLog7FPylYWt8yAJqcWm+cCQHXZafT5rH8ilkiHo1 yjqmtpmoQJAJzNjjhXUGGIAlzRt+RA3CmaxY6x7my9FYzHXe6FpZ90pnCzzDJyAiJz 9pq9RfG/4o0OfpQRUKvcmNXxjk4jTnfx9wm0GnoEeFUiWgmkpFRgaiUhjdSklZb676 Oo4KNvBfgGC7KyMgrCc5C3eeaOPAqclVpr84x1VJ30ZUwHBuRxInaH8q1cDA4D5nch Gv13w9CQb0noA== 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 v5 1/9] tpm: Cap the number of PCR banks Date: Wed, 1 Oct 2025 02:19:50 +0300 Message-Id: <20250930231958.1437783-2-jarkko@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250930231958.1437783-1-jarkko@kernel.org> References: <20250930231958.1437783-1-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. Cap the limit to four banks so that out of bounds values coming from external I/O cause on only limited harm. Cc: Roberto Sassu Fixes: bcfff8384f6c ("tpm: dynamically allocate the allocated_banks array") Signed-off-by: Jarkko Sakkinen --- v4: - Revert spurious changes from include/linux/tpm.h. - Increase TPM2_MAX_BANKS to 8. - Rename TPM2_MAX_BANKS as TPM2_MAX_PCR_BANKS for the sake of clarity. v3: - Wrote a more clear commit message. - Fixed pr_err() message. 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 | 8 +++++--- 5 files changed, 17 insertions(+), 38 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..97501c567c34 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_PCR_BANKS) { + pr_err("tpm: unexpected number of banks: %u > %u", + nr_possible_banks, TPM2_MAX_PCR_BANKS); rc =3D -ENOMEM; goto out; } diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 900c81a2bc41..f998dca4ea07 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -27,7 +27,9 @@ #include =20 #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 TPM2_MAX_PCR_BANKS 8 =20 struct tpm_chip; struct trusted_key_payload; @@ -69,7 +71,7 @@ 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 +192,7 @@ 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_PCR_BANKS]; #ifdef CONFIG_ACPI acpi_handle acpi_dev_handle; char ppi_version[TPM_PPI_VERSION_LEN + 1]; --=20 2.39.5