From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 C059B3254B2; Sun, 7 Jun 2026 10:24:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780827874; cv=none; b=Z5LBy+7AkGVgjWolc8zAKoCSiRBv3TRZRalQvuwRHAQ+LaR1YWzhy36w5oj0DmR+6WkXBrgVnex1rOvc6U2ftPyGsofFZVN6s2PqjmSRXsMxxFsvET18czd4EkkO0vbbMNsSQfxuytsk8fksusaRSxmu0ifgIvLCbAtd9tknB+M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780827874; c=relaxed/simple; bh=m/p+9igKWARo/WGxNc4ofs4krwYqXgcTb4f3eDvjRdo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=X6sedg5fKszdPf6wAM4vkE/RiO04BSv9zsg/ozo2fYmSp59sefXq6ufEIvNswGe887FoyrPQbcdPYvzWPUgUg7tmoNFqxy70OED1LshqA4s2dy2EG6ZBQZgqxU3fdai8h0rGx1QGHNLBiNVIyf07ZGEYwZckLRCxDJcQIlvSGU4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Bvth/RxU; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Bvth/RxU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97E831F00893; Sun, 7 Jun 2026 10:24:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780827873; bh=uk2CZfZAub7Z0XoEURnGx6d0+FcaGp5JEVLwk1Tz9lE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Bvth/RxUSWtarQasduwrbDcdl/JGpSpJ3F10AtEaXoCuuWUFMhjkg+sgu45Co59po 6KyouFwVVLxTv5p1rnNdPBlspJ/i0Ns8tQ4u0y5zKEGkMZ0oUVvkKSzxnt4l5DksGs EQBiW4AQ2R1brRyG0AiqjWlQJ2SJiRzZJS6THVpk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Badhri Jagan Sridharan , Heikki Krogerus , stable Subject: [PATCH 6.18 109/315] usb: typec: tcpm: bound altmode_desc[] per iteration in svdm_consume_modes() Date: Sun, 7 Jun 2026 11:58:16 +0200 Message-ID: <20260607095731.647268756@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260607095727.528828913@linuxfoundation.org> References: <20260607095727.528828913@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kroah-Hartman commit 3389c149c68c3fea61910ad5d34f7bf3bff44e32 upstream. svdm_consume_modes() checks pmdata->altmodes against the array size once before the loop over the count, but forgot to check the bound at every point in the loop. In the well-behaved SVDM discovery flow this is harmless because each of at most SVID_DISCOVERY_MAX SVIDs contributes at most MODE_DISCOVERY_MAX modes, exactly filling altmode_desc[ALTMODE_DISCOVERY_MAX]. But the CMDT_RSP_ACK handler in tcpm_pd_svdm() does not correlate an incoming ACK with any request the port actually sent. Once port->partner is set, an unsolicited Discover Modes ACK is consumed unconditionally. A broken or malicious port partner can therefore drive altmodes to ALTMODE_DISCOVERY_MAX - 1 via the normal flow, and then send one extra Discover Modes ACK with seven VDOs. Because the pre-loop check passes, the loop could then writes up to five entries past altmode_desc[]. For mode_data_prime the next field in struct tcpm_port is the partner_altmode[] pointer array, which then receives partner-chosen SVID/VDO bytes. Move the bound check inside the loop so the array can never be indexed past ALTMODE_DISCOVERY_MAX regardless of how many VDOs the partner supplies or how the function was reached. Assisted-by: gkh_clanker_t1000 Cc: Badhri Jagan Sridharan Cc: Heikki Krogerus Cc: stable Link: https://patch.msgid.link/2026051351-reshuffle-skillful-90af@gregkh Signed-off-by: Greg Kroah-Hartman --- drivers/usb/typec/tcpm/tcpm.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -1832,23 +1832,19 @@ static void svdm_consume_modes(struct tc switch (rx_sop_type) { case TCPC_TX_SOP_PRIME: pmdata = &port->mode_data_prime; - if (pmdata->altmodes >= ARRAY_SIZE(port->plug_prime_altmode)) { - /* Already logged in svdm_consume_svids() */ - return; - } break; case TCPC_TX_SOP: pmdata = &port->mode_data; - if (pmdata->altmodes >= ARRAY_SIZE(port->partner_altmode)) { - /* Already logged in svdm_consume_svids() */ - return; - } break; default: return; } for (i = 1; i < cnt; i++) { + if (pmdata->altmodes >= ALTMODE_DISCOVERY_MAX) { + /* Already logged in svdm_consume_svids() */ + return; + } paltmode = &pmdata->altmode_desc[pmdata->altmodes]; memset(paltmode, 0, sizeof(*paltmode));