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 93A603A16AC; Tue, 16 Jun 2026 16:11:19 +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=1781626280; cv=none; b=UVyznwtCyKooDh4NioBf4/yf9YE2rgPzEFuk3HFUrpBTTKn9Hujrpn1BRvplkDZrqsqF5jToMFwylKEpTy+JaTcbvjhbpG63biolUZ0hpD3Ir8CgJHd+jaQOUFPgUXJLfDhEVHNFjpvciDsgVfbrdOpyNZFGUvD4tkXyprMiVPc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781626280; c=relaxed/simple; bh=QLhY2zZNHA092a9hB3l36+JpeM58ujRKHeY/ACY862o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uClo6MUeE6hxtD7s1xoTwr3ZUug+3vY453N7rOwDXr0pgQwUuELIaray19DBSY2EM81ftwysh0wcA8RtL0tufghKWTyY6LkOeEo5bFxZk0Ii5uHmveMxcvir97pgeB/moQ0oE12KHqkp/ofGnl+UyPE4cpX+t2hnDAXEZv68ERY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=txURffno; 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="txURffno" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 76F0C1F000E9; Tue, 16 Jun 2026 16:11:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781626279; bh=avFXIH+eVE/9oqxWjNWWvNp0C0KYXIXQA6Qevfx+D9A=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=txURffnoTUg2YZq7VkMyhhCZA3YEWi8c1F+kpMYNCbzn6QouGfuXmzWhIaP693T6s OgsWYZa6rDrZAmPQX+EyS9+Nqm3Ux8osab+ZmR2MSUnhXecGAsyx5NTzrNpyg8b/ez Sz6+qVtQFRZBJtFzAIU+F2lxtIn0hfXQaIJMPLvg= 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 6.18 298/325] drm/amd/display: Clamp HDMI HDCP2 rx_id_list read to buffer size Date: Tue, 16 Jun 2026 20:31:34 +0530 Message-ID: <20260616145113.738928816@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145057.827196531@linuxfoundation.org> References: <20260616145057.827196531@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: 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 @@ -529,7 +529,8 @@ 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; }