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 D861138F930; Tue, 16 Jun 2026 17:10:51 +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=1781629852; cv=none; b=SuuUriA42a4oQqZ7mlIPkhdmtGDnFYbiNU3ivuZ9IU3DucEgqhjKtVjoOqpaFyAK/UyWKLV4bBjRD3RCNeh5P/EdavtJwmafL2JkEyf5SP97sIZKCzotn3kFQonWH1D17NfpycUbuqFanagFfQHmPrGIqt7ejkhQSNBK/nq1TkM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781629852; c=relaxed/simple; bh=pxDFPK/LuuCWLJUCKhROX9QupZho5jbq4MY/BHwJWzQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CeHYVshfAnnRvLTaYrwpLFxpt7R4nB2vgJeAn8ZcNn1RJ66A7aSKqh/+NsQiW3L1AgUZOaSUcyQB4GZdvnaRTmyAnkY0stf9kFgaswqSWKX2xgE/k1qd3rV4zYJOPl84TLszqomOAou6WNrXThIMIeoDOWkong0/m1wypZkSPsI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VnDnVEjR; 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="VnDnVEjR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A1D9D1F000E9; Tue, 16 Jun 2026 17:10:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781629851; bh=IoVgoiKC4sRfHqoT0OAK7Gu6fSthWU4xs5MCOGQNne0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VnDnVEjRXOWwwk3wdO4FRhrP+fFez3d//OxzXnK8LZVwK6sNbUGrHcrNfZAFC+UKK /OIzGVd9kp+1eKzwxQrC2e+w4TsGRV3yXxvHnhqHiFiAI1Xa5lHecsQBUtQFzqHfCm cgT29yHiQGaE4tfFdIzLYHLyQ9oHS34liBXiWHXc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alex Hung , Harry Wentland , Ray Wu , Daniel Wheeler , Alex Deucher Subject: [PATCH 6.6 364/452] drm/amd/display: Clamp HDMI HDCP2 rx_id_list read to buffer size Date: Tue, 16 Jun 2026 20:29:51 +0530 Message-ID: <20260616145136.206279971@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145117.796205997@linuxfoundation.org> References: <20260616145117.796205997@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Harry Wentland commit f0f3981c43b32cadfe373d636d9e9ca522bb3702 upstream. [Why & How] During HDCP 2.x repeater authentication over HDMI, the driver reads the sink's RxStatus register and extracts a 10-bit message size field (max value 1023). This value is used as the read length for the ReceiverID list without being clamped to the size of the destination buffer rx_id_list[177]. A malicious HDMI repeater could advertise a message size larger than the buffer, causing an out-of-bounds write during the I2C read. Clamp the read length in mod_hdcp_read_rx_id_list() to the size of the rx_id_list buffer, matching the approach already used in the DP branch. Fixes: eff682f83c9c ("drm/amd/display: Add DDC handles for HDCP2.2") Assisted-by: Copilot:claude-opus-4.6 Reviewed-by: Alex Hung Signed-off-by: Harry Wentland Signed-off-by: Ray Wu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 229212219e4247d9486f8ba41ef087358490be09) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c +++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c @@ -533,7 +533,8 @@ enum mod_hdcp_status mod_hdcp_read_rx_id } else { status = read(hdcp, MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_SEND_RECEIVERID_LIST, hdcp->auth.msg.hdcp2.rx_id_list, - hdcp->auth.msg.hdcp2.rx_id_list_size); + MIN(hdcp->auth.msg.hdcp2.rx_id_list_size, + sizeof(hdcp->auth.msg.hdcp2.rx_id_list))); } return status; }