From mboxrd@z Thu Jan 1 00:00:00 1970 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 5CD523DA7E1; Tue, 16 Jun 2026 18:32:15 +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=1781634736; cv=none; b=tUFftkyCS+nshQPo7PEQQZZdM/KRY+QCISfyufSbBAMIrkExisuNYbDWi8n4crKpAQI+wROk7YVQ6cWAptEHkdxHQG3bHq2hSN8vO+eLmKO3vrGkbPz0kfvOijE/WWf/1E2Hdxfd75gbHq+pA05CHG1wPdv/zg8jIHpkPZ0tR3k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781634736; c=relaxed/simple; bh=5jvaTpUL4fsOCin9HT7dhm3eoHSIm1JVWOXrxhw+KPs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=a5NPHrzPPR8l+EALIZa9ebazgom5QLW9FfFbVznm4YMCHU4CRfvyl/XfEwcSsGtlFZSSvJ9Bm9992H1qH5MCzAqXiLj/QKB8cIRDYVFQ/dAOSQRT0NY/kTt96KmLtTSxBhBRLrnT7ZuTzcFoAoqiFdckw714SRNGPbZKPOxBhhk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0G3SwVJl; 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="0G3SwVJl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F10B71F000E9; Tue, 16 Jun 2026 18:32:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781634735; bh=lgzEEp3cPCZvuF2nJux1GQ/z5VOtnecEHxYxq8yvo+o=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=0G3SwVJlec814Lbh6QkqAw7G2spx7WZh6xlcl0KpCLdEzu2EULLCt7GooC4iwVvMu ijQ6vRKyQYDzBmxvK+OAuB/15oy2EAwVLoOChTHsukkb/eIM8ncRZd3NTrdIkkee3F YctHIh8IrnO6bO9LnixOulzuTr92+1T8GyY0VObk= 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 5.15 321/411] fbcon: Avoid OOB font access if console rotation fails Date: Tue, 16 Jun 2026 20:29:19 +0530 Message-ID: <20260616145118.218529226@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145100.376842714@linuxfoundation.org> References: <20260616145100.376842714@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 5.15-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; }