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 659FB2DEA79; Wed, 3 Dec 2025 22:12:32 +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=1764799953; cv=none; b=l8In0THkBpDfUYrJZaZBPZ2A9aVQyRRQ26aE8iv5erwrg7RPRLO/T4BQOuNrcbCTWyvNh6tPHSoY5UPAvWFM4YL/Hiy5mX7dluROirbfAfJ2SEuFksx5WZJh0WA4Teu4NFLpFdT2BgDwlNeM0Vy8ARQT/4iWIOnvpI+bpRtnqkA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764799953; c=relaxed/simple; bh=pEroIieDV0yILHi+qd0Kw6/doaQeGzsOJ0pf58PbQwA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WaTSy1eEJYCy4OSqNed6cWDNZFlOuITGkjR4tGs8t8F2twMne2+RgKCOJBAM6lnja9Z9VT0d+L/eY/uXKO1DIWs4zQ9icJGshh8Q5LKJKc2G3prlNytTxuc4hn0Xd/H9MuN+DSMM/XAD7IVVj/4nnDpRrbq34IoPHumrISmACdo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=C0DZty2n; 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="C0DZty2n" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2FF99C116C6; Wed, 3 Dec 2025 22:12:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764799952; bh=pEroIieDV0yILHi+qd0Kw6/doaQeGzsOJ0pf58PbQwA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C0DZty2n2AhAGmyoQKq5vTxejWi8Z74IGkDyFZRWRqVpHzn3w/aZ9g/h4YfZx920I XwTzOtS5r/KmufN+l+QIwUYL/HDd2JV1vkGn7KHEAnulXcJrUkiBq7oTlnV18YXm8H 07hicCXbjstV4RQ//0H2CD5WOShsYwn9J31n177Ry3Co8EHVoD071BDMNiT0ejDKAM MdYkE2Q561T5LexBPie0NW7SqbpXNcrR/+tno2wfoh+Bbq13Z0GXxB4dmY74TOdMWc 7MJntUlXKWqxet0SuFVY7O8lesTfqflHHd3i9v0Q4dhVm+a7B7u5AvZsDEHu/cYzPv mnARD1agS+8cg== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , Jonathan McDowell , Peter Huewe , Jason Gunthorpe , linux-kernel@vger.kernel.org (open list), stable@vger.kernel.org, James Bottomley , Ard Biesheuvel Subject: [PATCH v3 2/4] tpm2-sessions: Fix tpm2_read_public range checks Date: Thu, 4 Dec 2025 00:12:12 +0200 Message-ID: <20251203221215.536031-3-jarkko@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251203221215.536031-1-jarkko@kernel.org> References: <20251203221215.536031-1-jarkko@kernel.org> Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 'tpm2_read_public' has some rudimentary range checks but the function does not ensure that the response buffer has enough bytes for the full TPMT_HA payload. Re-implement the function with necessary checks and validation. Cc: stable@vger.kernel.org # v6.10+ Fixes: d0a25bb961e6 ("tpm: Add HMAC session name/handle append") Signed-off-by: Jarkko Sakkinen v2: - Made the fix localized instead of spread all over the place. --- drivers/char/tpm/tpm2-cmd.c | 3 ++ drivers/char/tpm/tpm2-sessions.c | 77 +++++++++++++++++--------------- 2 files changed, 44 insertions(+), 36 deletions(-) diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index be4a9c7f2e1a..34e3599f094f 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -11,8 +11,11 @@ * used by the kernel internally. */ +#include "linux/dev_printk.h" +#include "linux/tpm.h" #include "tpm.h" #include +#include static bool disable_pcr_integrity; module_param(disable_pcr_integrity, bool, 0444); diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index a265e9752a5e..e9f439be3916 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -163,54 +163,59 @@ static int name_size(const u8 *name) } } -static int tpm2_parse_read_public(char *name, struct tpm_buf *buf) +static int tpm2_read_public(struct tpm_chip *chip, u32 handle, void *name) { - struct tpm_header *head = (struct tpm_header *)buf->data; + u32 mso = tpm2_handle_mso(handle); off_t offset = TPM_HEADER_SIZE; - u32 tot_len = be32_to_cpu(head->length); - int ret; - u32 val; - - /* we're starting after the header so adjust the length */ - tot_len -= TPM_HEADER_SIZE; - - /* skip public */ - val = tpm_buf_read_u16(buf, &offset); - if (val > tot_len) - return -EINVAL; - offset += val; - /* name */ - - val = tpm_buf_read_u16(buf, &offset); - ret = name_size(&buf->data[offset]); - if (ret < 0) - return ret; + struct tpm_buf buf; + int rc, rc2; - if (val != ret) + if (mso != TPM2_MSO_PERSISTENT && mso != TPM2_MSO_VOLATILE && + mso != TPM2_MSO_NVRAM) return -EINVAL; - memcpy(name, &buf->data[offset], val); - /* forget the rest */ - return 0; -} - -static int tpm2_read_public(struct tpm_chip *chip, u32 handle, char *name) -{ - struct tpm_buf buf; - int rc; - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_READ_PUBLIC); if (rc) return rc; tpm_buf_append_u32(&buf, handle); - rc = tpm_transmit_cmd(chip, &buf, 0, "read public"); - if (rc == TPM2_RC_SUCCESS) - rc = tpm2_parse_read_public(name, &buf); - tpm_buf_destroy(&buf); + rc = tpm_transmit_cmd(chip, &buf, 0, "TPM2_ReadPublic"); + if (rc) { + tpm_buf_destroy(&buf); + return tpm_ret_to_err(rc); + } - return rc; + /* Skip TPMT_PUBLIC: */ + offset += tpm_buf_read_u16(&buf, &offset); + + /* + * Ensure space for the length field of TPM2B_NAME and hashAlg field of + * TPMT_HA (the extra four bytes). + */ + if (offset + 4 > tpm_buf_length(&buf)) { + tpm_buf_destroy(&buf); + return -EIO; + } + + rc = tpm_buf_read_u16(&buf, &offset); + rc2 = name_size(&buf.data[offset]); + + if (rc2 < 0) + return rc2; + + if (rc != rc2) { + tpm_buf_destroy(&buf); + return -EIO; + } + + if (offset + rc > tpm_buf_length(&buf)) { + tpm_buf_destroy(&buf); + return -EIO; + } + + memcpy(name, &buf.data[offset], rc); + return 0; } #endif /* CONFIG_TCG_TPM2_HMAC */ -- 2.52.0