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 E75F02F3605; Tue, 2 Dec 2025 20:27:00 +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=1764707221; cv=none; b=eDvuuSW2aHVaGfGsTOyR/CwS/QtAwWpBm7C9DivTTTUMkJ6sMntvXWhG1nYnVA5TzWlBd2UqqS2zwqZJHglJzXei2SlfH45U68v9jCVaxRq1R2T4spoAfFpFxD4nQOYqtmF6fbARGTvuoHo6iANjtNE0bFH2GZHrwJTmgbTR32Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764707221; c=relaxed/simple; bh=A+KBwrEGw+Q66tMB4kTs9WcRGbEetXnPSCqTR053tDw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lgXUTaCA6M1zA0WDAcNMpUWCFSmj97I4NMFRSYnTN4nSVvAsp7q3hLIc+dMUC+xfx/v4YRDfZ4/xCANHuZb5k5afNubS/SJg158L539fFWeoi8IVjJwq0QN/pZn1H5ADIq4Klb2M0VsHYO0BtDE36S+x0iZSDWdgVO6bmKWbiBE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QFIapIWz; 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="QFIapIWz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5561AC4CEF1; Tue, 2 Dec 2025 20:27:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764707220; bh=A+KBwrEGw+Q66tMB4kTs9WcRGbEetXnPSCqTR053tDw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QFIapIWzY+MIBJRg1ScP2oZerWjda600/KK2nRiuO1AtMLARD85UfgzRL5pQW6irK qZcPJ8AWrNSucLAt6yWG8Hr6nkAxLWd7WITajMeG5QFYLQXvw2tdzl29RCuG4r6E4X 5dpAhq0t030HL+nauGxOPEwImOwoK48V2OAdrmQ7hk0IUrJSyQ/heldRGsF0ZvjokJ GWvMovmnWn+QMLYtBDF6f+RY69LhJWz36XiSsZySikguaFKQWAVxzKyI8G6ptPH+z1 D5qzT98EVSA/5wlhZMTvf7XwJ2iQuOyVeeAvCPzjED10aCTt/MfSyE7eBYxVIUKpEl ReTrm3XE5Y7rw== 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 v2 2/4] tpm2-sessions: Fix tpm2_read_public range checks Date: Tue, 2 Dec 2025 22:26:39 +0200 Message-ID: <20251202202643.107108-3-jarkko@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251202202643.107108-1-jarkko@kernel.org> References: <20251202202643.107108-1-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 --- 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 4473b81122e8..58a8477cda85 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 dc6bee7e1ef6..964f44c2255d 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