From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86073C4708A for ; Mon, 28 Nov 2022 17:48:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233745AbiK1RsS (ORCPT ); Mon, 28 Nov 2022 12:48:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233988AbiK1Rru (ORCPT ); Mon, 28 Nov 2022 12:47:50 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1A33E2E9CB; Mon, 28 Nov 2022 09:43:00 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id ADCF9612D2; Mon, 28 Nov 2022 17:42:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7FEFC433C1; Mon, 28 Nov 2022 17:42:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669657379; bh=mbictxFnrB8hQp4pZs8liuotbQ0GOAJnYD3SqqbJ0No=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t5pPLWpAbfw1j2xId+6yNsYFmArEd41hdlq8ihknTkVbatMLBsD3ete2jvDNFXViP ebqJPKaE28oaV7uVJqOJMIFhsjTp9SEv5zbUAGktaqldIYIyDA42XQ04fNioi5FUV1 kDuCd+raoDQJPPMvwU98f7VPl+dbYiUXwotzENAOoK7XsnIQy5GAjMBKbABXQYB9g6 +GBiyRTx52zAY+Xs/jBWTUlfIy7wrLXulR7uBfNEjjEtuhi2BXJetSrdQ8YO8Ml+cQ 2Iww14I3IZhuLYUC0v0iuEjKVfJ14moQ2GrWgo99n0RioafAwe5ewzoEuTKbKEGtkp 57V2y0Q1K5ruA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tetsuo Handa , Daniel Vetter , Sasha Levin , daniel@ffwll.ch, deller@gmx.de, sam@ravnborg.org, tzimmermann@suse.de, geert+renesas@glider.be, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 4.19 10/12] fbcon: Use kzalloc() in fbcon_prepare_logo() Date: Mon, 28 Nov 2022 12:42:33 -0500 Message-Id: <20221128174235.1442841-10-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221128174235.1442841-1-sashal@kernel.org> References: <20221128174235.1442841-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org From: Tetsuo Handa [ Upstream commit a6a00d7e8ffd78d1cdb7a43f1278f081038c638f ] A kernel built with syzbot's config file reported that scr_memcpyw(q, save, array3_size(logo_lines, new_cols, 2)) causes uninitialized "save" to be copied. ---------- [drm] Initialized vgem 1.0.0 20120112 for vgem on minor 0 [drm] Initialized vkms 1.0.0 20180514 for vkms on minor 1 Console: switching to colour frame buffer device 128x48 ===================================================== BUG: KMSAN: uninit-value in do_update_region+0x4b8/0xba0 do_update_region+0x4b8/0xba0 update_region+0x40d/0x840 fbcon_switch+0x3364/0x35e0 redraw_screen+0xae3/0x18a0 do_bind_con_driver+0x1cb3/0x1df0 do_take_over_console+0x11cb/0x13f0 fbcon_fb_registered+0xacc/0xfd0 register_framebuffer+0x1179/0x1320 __drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40 drm_fbdev_client_hotplug+0xbea/0xda0 drm_fbdev_generic_setup+0x65e/0x9d0 vkms_init+0x9f3/0xc76 (...snipped...) Uninit was stored to memory at: fbcon_prepare_logo+0x143b/0x1940 fbcon_init+0x2c1b/0x31c0 visual_init+0x3e7/0x820 do_bind_con_driver+0x14a4/0x1df0 do_take_over_console+0x11cb/0x13f0 fbcon_fb_registered+0xacc/0xfd0 register_framebuffer+0x1179/0x1320 __drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40 drm_fbdev_client_hotplug+0xbea/0xda0 drm_fbdev_generic_setup+0x65e/0x9d0 vkms_init+0x9f3/0xc76 (...snipped...) Uninit was created at: __kmem_cache_alloc_node+0xb69/0x1020 __kmalloc+0x379/0x680 fbcon_prepare_logo+0x704/0x1940 fbcon_init+0x2c1b/0x31c0 visual_init+0x3e7/0x820 do_bind_con_driver+0x14a4/0x1df0 do_take_over_console+0x11cb/0x13f0 fbcon_fb_registered+0xacc/0xfd0 register_framebuffer+0x1179/0x1320 __drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40 drm_fbdev_client_hotplug+0xbea/0xda0 drm_fbdev_generic_setup+0x65e/0x9d0 vkms_init+0x9f3/0xc76 (...snipped...) CPU: 2 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc4-00356-g8f2975c2bb4c #924 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 ---------- Signed-off-by: Tetsuo Handa Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/cad03d25-0ea0-32c4-8173-fd1895314bce@I-love.SAKURA.ne.jp Signed-off-by: Sasha Levin --- drivers/video/fbdev/core/fbcon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index 417f4bcc1182..9fcd583b7835 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -579,7 +579,7 @@ static void fbcon_prepare_logo(struct vc_data *vc, struct fb_info *info, if (scr_readw(r) != vc->vc_video_erase_char) break; if (r != q && new_rows >= rows + logo_lines) { - save = kmalloc(array3_size(logo_lines, new_cols, 2), + save = kzalloc(array3_size(logo_lines, new_cols, 2), GFP_KERNEL); if (save) { int i = cols < new_cols ? cols : new_cols; -- 2.35.1