From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B20848F57 for ; Mon, 13 Feb 2023 15:02:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3A202C4339E; Mon, 13 Feb 2023 15:02:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1676300542; bh=KUdffbF/dZC/D0O7OjzI/Xc30IbsG6zqH2IJB/r+r5E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DDAcOoqEa4nuboNy9essXx72xnqoyps0wuzvM5ryYwyYxkCH3u5PebVX7wRdxFwPp uRVLajPZwQInKwC0VV89DQH9/E5f+S48rtl9kYt8OOlbXqwcLvQ7pjsuMjbMGN/pOQ E4Msyy3SawyHK9HAzCghvYWb1B6Vi1u5CE6YEMhg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sanan Hasanov , Samuel Thibault , Miko Larsson , Helge Deller Subject: [PATCH 5.10 054/139] fbcon: Check font dimension limits Date: Mon, 13 Feb 2023 15:49:59 +0100 Message-Id: <20230213144748.590164151@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230213144745.696901179@linuxfoundation.org> References: <20230213144745.696901179@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Samuel Thibault commit 2b09d5d364986f724f17001ccfe4126b9b43a0be upstream. blit_x and blit_y are u32, so fbcon currently cannot support fonts larger than 32x32. The 32x32 case also needs shifting an unsigned int, to properly set bit 31, otherwise we get "UBSAN: shift-out-of-bounds in fbcon_set_font", as reported on: http://lore.kernel.org/all/IA1PR07MB98308653E259A6F2CE94A4AFABCE9@IA1PR07MB9830.namprd07.prod.outlook.com Kernel Branch: 6.2.0-rc5-next-20230124 Kernel config: https://drive.google.com/file/d/1F-LszDAizEEH0ZX0HcSR06v5q8FPl2Uv/view?usp=sharing Reproducer: https://drive.google.com/file/d/1mP1jcLBY7vWCNM60OMf-ogw-urQRjNrm/view?usp=sharing Reported-by: Sanan Hasanov Signed-off-by: Samuel Thibault Fixes: 2d2699d98492 ("fbcon: font setting should check limitation of driver") Cc: stable@vger.kernel.org Tested-by: Miko Larsson Reviewed-by: Greg Kroah-Hartman Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman --- drivers/video/fbdev/core/fbcon.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -2513,9 +2513,12 @@ static int fbcon_set_font(struct vc_data h > FBCON_SWAP(info->var.rotate, info->var.yres, info->var.xres)) return -EINVAL; + if (font->width > 32 || font->height > 32) + return -EINVAL; + /* Make sure drawing engine can handle the font */ - if (!(info->pixmap.blit_x & (1 << (font->width - 1))) || - !(info->pixmap.blit_y & (1 << (font->height - 1)))) + if (!(info->pixmap.blit_x & BIT(font->width - 1)) || + !(info->pixmap.blit_y & BIT(font->height - 1))) return -EINVAL; /* Make sure driver can handle the font length */