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 587D2355042; Wed, 7 Jan 2026 16:16:09 +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=1767802570; cv=none; b=mQhuodZI+nIGy1E8MrRTu3Q5QHf6nLQKoD9eKlOrUUYHQDIfMhwjdvm1AgPAFbdto5kxog/BrjyUJc2U5lzFlVuF2igxfvcFwsROVpA8oZ+39tQBMHY2lqxV0EuU91rSFrNqe9FGK32tuXMibjQzWtAnPOEhYhJsyrKJ/5jqGA4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767802570; c=relaxed/simple; bh=10JTA/GF2GbzhsA7K1qACneMcHSQxQXMbTewSt7FuaM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Y/Er6z97PHkWOYeb7giwphgZptFzmy5fBsFo63jgYb6M8LbXK5M5uvVKjTxtocPW2DBUS1SCUJO9bZR9PK1qMSbBRCU0vUXz9i5VC9i3A8rD3EcdfWpHbO0trVdO4V1kQZI1ZrwXtqQHhy49PRi2a6ToBTtn3zYWFkda1dAmcRA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GxaXArPo; 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="GxaXArPo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 33306C4CEF1; Wed, 7 Jan 2026 16:16:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767802568; bh=10JTA/GF2GbzhsA7K1qACneMcHSQxQXMbTewSt7FuaM=; h=From:To:Cc:Subject:Date:From; b=GxaXArPoRxWT6qmCAHJ+c+bTwrWzvq7hEuqbxq8LF4zMfE9kgAm4jnDegqOX7nOdz WBWcdvx68HS8JA/73IiGDJU0nMIU76tN1oeubb6MAhNbaVsk99pZSTIweuABXrkwdY YQoBeBDX5wputixsAoa4feF8i0kS4ujjw4Lvd+9ejmEbsX8/2IDvmy6oA1LqHFgNoK jRo2vPEhRcQwTT2JmkMbk6zoxKiYUEGnuwW7/yiwbEhqN9RuQAVrpphXC9vSA9vXN5 ANDm7kHOOaCstdYF7Tj61cNuHvSg15Q68umTpcWEMnc5nd+xKsArdOSIPn/Xy8atdo YT/a3lVaeCbOw== From: Jarkko Sakkinen To: stable@vger.kernel.org Cc: linux-integrity@vger.kernel.org, Jarkko Sakkinen , Lai Yi , Jonathan McDowell , Roberto Sassu Subject: [PATCH] tpm: Cap the number of PCR banks Date: Wed, 7 Jan 2026 18:15:51 +0200 Message-ID: <20260107161551.53475-1-jarkko@kernel.org> X-Mailer: git-send-email 2.52.0 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 --- Backport for v5.10, v5.15, v6.1 and v6.6 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 | 8 +++++--- 4 files changed, 8 insertions(+), 14 deletions(-) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 70e3fe20fdcf..458a3e9ea73a 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -279,7 +279,6 @@ 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 cf64c7385105..b49a790f1bd5 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -799,11 +799,6 @@ 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 93545be190a5..57bb3e34b770 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 bf8a4ec8a01c..f5e7cca2f257 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -25,7 +25,9 @@ #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 TPM2_MAX_PCR_BANKS 8 struct tpm_chip; struct trusted_key_payload; @@ -51,7 +53,7 @@ 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 +159,7 @@ 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]; -- 2.52.0