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 19D4B3C4B72; Fri, 15 May 2026 16:15:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778861735; cv=none; b=uTlBeyeHUskP409BmawOeMaHVYNWvV/rW8hD+Sw+VgUYf4qnm0CIoyiQfUqczESbPM5BWBI4Hi7jCefJEB7mZLSQ313FQJZ7DT1XSaRu9IFt5Ava7VIdYaGGn9ybvyy59PWFv0Ilt7GwFPIZH/RdrJwNUHmsDBUFp9LsJjXb4y0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778861735; c=relaxed/simple; bh=yVEkMIKjDKVJxU6XRLYMAUxlcB0kUyELftCRD4YAHxg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ObtWCSn2kp9ntSp8HE++sdbqA2HNnZ5lL3LLLj6q3fedmAIHYho9gIgi/+nPsM9CmcKWhMxbBxJTyE/MhQaVN4lwBLj+C9WVErZzBxqrKkPDXAXYleB1w3cnygdrlwt4iIq6Xhj3Wwou3NsNnSazMuO9E1kNCMsW1dco+Bmhca0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Y64t86wg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Y64t86wg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A68B1C2BCB0; Fri, 15 May 2026 16:15:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778861735; bh=yVEkMIKjDKVJxU6XRLYMAUxlcB0kUyELftCRD4YAHxg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y64t86wgP0d/7FHlefMkA/8YvibuKc55Vvr3yHs60NGAn1WYAuJVabejBAtWq9rHG Vo2X6gvnjPMoyNh6ZXwM8e/scc+FCPkeOaCiH2vrSMXMZJ6/txK43QDL1NzDh9RUyr S6Y5zSDhi2nwTte19PNvXvub4PZieOMxtkLalYcs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Thomas Zimmermann , Helge Deller , Sasha Levin Subject: [PATCH 6.6 443/474] fbcon: Avoid OOB font access if console rotation fails Date: Fri, 15 May 2026 17:49:12 +0200 Message-ID: <20260515154724.672461274@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260515154715.053014143@linuxfoundation.org> References: <20260515154715.053014143@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org 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: Thomas Zimmermann [ Upstream commit e4ef723d8975a2694cc90733a6b888a5e2841842 ] Clear the font buffer if the reallocation during console rotation fails in fbcon_rotate_font(). The putcs implementations for the rotated buffer will return early in this case. See [1] for an example. Currently, fbcon_rotate_font() keeps the old buffer, which is too small for the rotated font. Printing to the rotated console with a high-enough character code will overflow the font buffer. v2: - fix typos in commit message Signed-off-by: Thomas Zimmermann Fixes: 6cc50e1c5b57 ("[PATCH] fbcon: Console Rotation - Add support to rotate font bitmap") Cc: stable@vger.kernel.org # v2.6.15+ Link: https://elixir.bootlin.com/linux/v6.19/source/drivers/video/fbdev/core/fbcon_ccw.c#L144 # [1] Signed-off-by: Helge Deller [ renamed `par` to `ops` to match the 6.12 local pointer name ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/video/fbdev/core/fbcon_rotate.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/video/fbdev/core/fbcon_rotate.c +++ b/drivers/video/fbdev/core/fbcon_rotate.c @@ -46,6 +46,10 @@ static int fbcon_rotate_font(struct fb_i info->fbops->fb_sync(info); if (ops->fd_size < d_cellsize * len) { + kfree(ops->fontbuffer); + ops->fontbuffer = NULL; + ops->fd_size = 0; + dst = kmalloc_array(len, d_cellsize, GFP_KERNEL); if (dst == NULL) { @@ -54,7 +58,6 @@ static int fbcon_rotate_font(struct fb_i } ops->fd_size = d_cellsize * len; - kfree(ops->fontbuffer); ops->fontbuffer = dst; }