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 22FA6381B0A; Thu, 20 Aug 2026 15:21:19 +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=1787239281; cv=none; b=KhgesPjytJZpigj9cDz3S76R14LKCAQumu1SO2AfFr0vITbD4WnektnoH+VhmJqNMAWiPHmQYWvoUo1uqUc1F5bENNo+sfK7bU0Jnhn/Kj+PocxIazAAJH4068E35dpmmxz1VgCJ3Op9jfX9cbV6P0UEfy8Co0clxHIXu7Nj1CU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787239281; c=relaxed/simple; bh=HhzbMVTNavyUoAgJ1HgYzW//phPwy7HdTuwxGLNZYNE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RX9Xh0TK5qTQTyl6vmwZWMOLh6WZG+BRJXJwnIp9+xWKV0zjcKB9u0cPoq4OdxVBY2tShjuddmSY9bKneEs73mbGA4NGDNnx0bU6brkXxwwwIfL2UzJMrjZUlHn2wv8fqkNAFL3cpTFdJZ6bbZdPYGwLt3uRB5uiPr97cfmuOz0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fqt+45cD; 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="fqt+45cD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 422611F000E9; Thu, 20 Aug 2026 15:21:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787239279; bh=KtpRCTamsdwV2/uBtl3sKitKd9pc04Rx1oPyh8/3nDA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fqt+45cDIwAJxLq1+8018WHn8x3tjiXZomZIu8lH4PbZZNY7M9G/6A3NRZIZIcStz 8kQoA0FDtO7J7CxLFn3MqTWs32pOTQKTeWsRuXIzIq33s5ROKkCfWoDLwkEPyHitcv XTYbdhIaX4k96fmvyMmQ7G8mh0TTvG/A8NrZD6X0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shixiong Ou , Jocelyn Falempe , Sasha Levin Subject: [PATCH 6.18 213/217] drm/log: Fix infinite loop when scale is too large for display Date: Thu, 20 Aug 2026 16:56:21 +0200 Message-ID: <20260820145244.098387493@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260820145237.531699751@linuxfoundation.org> References: <20260820145237.531699751@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: Shixiong Ou [ Upstream commit f4f2bba28df9b9aaa00262a462139dbbcdc38d9f ] When scale is large enough that scaled_font exceeds the display dimensions, rows or columns become 0. A columns value of 0 causes an infinite loop in drm_log_draw_kmsg_record() because the loop never decrements len. Check for zero rows/columns in drm_log_setup_modeset() and return an error, cleaning up the already allocated buffer to avoid a leak. Fixes: 8a4b913df427 ("drm/log: Add integer scaling support") Signed-off-by: Shixiong Ou Reviewed-by: Jocelyn Falempe Link: https://patch.msgid.link/20260729084815.692944-1-oushixiong1025@163.com Signed-off-by: Jocelyn Falempe Signed-off-by: Sasha Levin --- drivers/gpu/drm/clients/drm_log.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/clients/drm_log.c b/drivers/gpu/drm/clients/drm_log.c index d040b55e5badd..1e137786b36a1 100644 --- a/drivers/gpu/drm/clients/drm_log.c +++ b/drivers/gpu/drm/clients/drm_log.c @@ -218,6 +218,12 @@ static int drm_log_setup_modeset(struct drm_client_dev *client, scanout->scaled_font_w = scanout->font->width * scale; scanout->rows = height / scanout->scaled_font_h; scanout->columns = width / scanout->scaled_font_w; + if (!scanout->rows || !scanout->columns) { + drm_client_buffer_delete(scanout->buffer); + scanout->buffer = NULL; + mode_set->fb = NULL; + return -EINVAL; + } scanout->front_color = drm_draw_color_from_xrgb8888(0xffffff, format); scanout->prefix_color = drm_draw_color_from_xrgb8888(0x4e9a06, format); return 0; -- 2.53.0