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 02BBA3FF1D8; Fri, 15 May 2026 15:55:19 +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=1778860519; cv=none; b=AMhDNQ3e348c0Dnss1JMctpYYPcEzsXoRFNadU+m8d14E8Srj1KBqJ6tjTwLNc2eJruMrYWUyYfgxiEOkGFBY/8CZ1S7+vnVjbA4WHhBIeQrzVM3EyIvueXIqvkXzmRtSNCC4LCMc4zv0RLpHG5G+DAjFicn2twg0SimJdQKopo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778860519; c=relaxed/simple; bh=cGkDbWum4ghFoFYoHvF541bMLiyBgSMnDuW6rBL//x8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Pa85vvZIC70QwXdktvJ3uKen4S5x+Vb6fKHrgaE6jwcFMwJL0rQeJuWOt6rrJrEscLlcBtflaaDs4NDSAeBdhfdbWorGjooDr5YB9AKIdjlJLy4M9ShI3doA266SduuqGPscFwWFgFvRnSaCeI9hzk/tfDt+mw6e26uoPjFsa1w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XD0ns8b6; 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="XD0ns8b6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8ABB0C2BCB3; Fri, 15 May 2026 15:55:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778860518; bh=cGkDbWum4ghFoFYoHvF541bMLiyBgSMnDuW6rBL//x8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XD0ns8b67BWuR/IO+RZZ3pjptx+pyaQceFwYbjlZ72M/ErDNBe+9fl1WB5yDYdT/1 TIAHaJ3Bot3juDOG20w4cWWI4SPuhFQLo5ib/x1lvYqOvFJ+wRMPJjupb/eHFETulr ulKEAgX5wAVMo8jLtGsHNYvaDIAKy3At46qeru8k= 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 6.12 121/144] fbcon: Avoid OOB font access if console rotation fails Date: Fri, 15 May 2026 17:49:07 +0200 Message-ID: <20260515154656.310918889@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260515154653.469907118@linuxfoundation.org> References: <20260515154653.469907118@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 6.12-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; }