From nobody Sun Feb 8 06:05:40 2026 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 30B24299A82; Mon, 1 Dec 2025 22:46:14 +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=1764629175; cv=none; b=PELo2YN45epvBMHtZ40/QO3mrZCDdPsMJWYG48a+SVpkAlg+ygX4PzDIV9wOqTaY0uCWVSpvpN/9Sjl3dlCzN2OAGWYOpUPYGwByF4SEZRTh4EOXzTcPIiSpqxoB0vGZdk9RcgHIig2XhYj71AaBMZftLxs+cc0YyysYNyZjP0Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764629175; c=relaxed/simple; bh=lghMIWcoAMO2UqemhgpnDfw0sFzpW4OPCayQxWihy9s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ebbrm7zCYyTpW2/40anqf9f2dazjvUoZZf+ZrVO7OO5ZA7ztpZlXF/4zKsK94r7CNsALcpDdJmjSebVYfdsGOdi0xSl9YR3ZyYlvFJaW7odk2HIP/ab0tt7aEvJD375hVZBNSmn6bJUImHdw1VUnbojQ8evTY+OYgAetX0qMqsA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rvN2fNhA; 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="rvN2fNhA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BB93C116D0; Mon, 1 Dec 2025 22:46:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764629174; bh=lghMIWcoAMO2UqemhgpnDfw0sFzpW4OPCayQxWihy9s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rvN2fNhAVuLoJjomO/F0AIE1wX4DUsINvWI6qYw2p2quBDkRnSeT30qXzbJ2RbGuG 425muwLSq5xZMLaXK4lTiBD0jk/WKw87vxEaOarSk8KFoqxm4Fp4FT/Ybi2TDshV2k BwCm5HbCrqipltBX8UJQefOFSE+vprCHRFlBARvp2UjQCX9ry3M8P6J0RP69thbcA2 5raUFW8VXYo4kmWfvXYez8/QEfiKWaPZjqalwh3ITMN73iUkZIJe1dFv4OL5JX2zbM LiU6KN5t3Y2W3QA+qm0a1aTPGMPKyu6G9aeAzvFXdlqNrSqs6RcmGF8Rt7WuZwgFsh AZfDqzKMEAxoQ== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , stable@vger.kernel.org, Peter Huewe , Jason Gunthorpe , James Bottomley , Ard Biesheuvel , linux-kernel@vger.kernel.org (open list) Subject: [PATCH 2/4] tpm2-sessions: Fix tpm2_read_public range checks Date: Tue, 2 Dec 2025 00:45:50 +0200 Message-ID: <20251201224554.1717104-3-jarkko@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251201224554.1717104-1-jarkko@kernel.org> References: <20251201224554.1717104-1-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" '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. */ =20 +#include "linux/dev_printk.h" +#include "linux/tpm.h" #include "tpm.h" #include +#include =20 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-sessi= ons.c index 33ad0d668e1a..afbca03f639e 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -164,54 +164,59 @@ static int name_size(const u8 *name) return -EINVAL; } =20 -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 =3D (struct tpm_header *)buf->data; + u32 mso =3D tpm2_handle_mso(handle); off_t offset =3D TPM_HEADER_SIZE; - u32 tot_len =3D be32_to_cpu(head->length); - int ret; - u32 val; - - /* we're starting after the header so adjust the length */ - tot_len -=3D TPM_HEADER_SIZE; - - /* skip public */ - val =3D tpm_buf_read_u16(buf, &offset); - if (val > tot_len) - return -EINVAL; - offset +=3D val; - /* name */ - - val =3D tpm_buf_read_u16(buf, &offset); - ret =3D name_size(&buf->data[offset]); - if (ret < 0) - return ret; + struct tpm_buf buf; + int rc, rc2; =20 - if (val !=3D ret) + if (mso !=3D TPM2_MSO_PERSISTENT && mso !=3D TPM2_MSO_VOLATILE && + mso !=3D TPM2_MSO_NVRAM) return -EINVAL; =20 - 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 =3D tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_READ_PUBLIC); if (rc) return rc; =20 tpm_buf_append_u32(&buf, handle); - rc =3D tpm_transmit_cmd(chip, &buf, 0, "read public"); - if (rc =3D=3D TPM2_RC_SUCCESS) - rc =3D tpm2_parse_read_public(name, &buf); =20 - tpm_buf_destroy(&buf); + rc =3D tpm_transmit_cmd(chip, &buf, 0, "TPM2_ReadPublic"); + if (rc) { + tpm_buf_destroy(&buf); + return tpm_ret_to_err(rc); + } =20 - return rc; + /* Skip TPMT_PUBLIC: */ + offset +=3D 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 =3D tpm_buf_read_u16(&buf, &offset); + rc2 =3D name_size(&buf.data[offset]); + + if (rc2 < 0) + return rc2; + + if (rc !=3D 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 */ =20 --=20 2.52.0