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 78448307AC7; Mon, 13 Apr 2026 16:38:51 +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=1776098331; cv=none; b=XR6Cc4p91YyH6yZ0GX4grSnM/I0Qd+fsPoj67m0v+n+f7Ua8VAOmtK8EAiAVTPudoOwELLZRpVSC7A9bvvDDJdOjCLm61p4lvWZGBWc27Ts6Z+SRjhJ44KQaTpZDEmJgSmAwEKVIL7mnx7kBSm4xeNfqE3hXXC4dHd2f+eNppr8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776098331; c=relaxed/simple; bh=lIDSzS9EPfSbfpVQdxtZEJ6jAzas17R+pEgeTxxnouE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eBrkGwevpVboYYiPENtEjb0PgLU1s8HqXjx7mUAlYS1Y7/Q93PGwz7wbJU4gf0eaVqS3tHJG0rgezPSqLHS35Sg++nLIG4Fer/jxZj5eYpVJ2tQ7NHql5WOvMeyJe5s+EJ6cI1yXwJnyM/Quv3o+TKWz3rrstORj+gJf8+wPHDk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=uz7W6K9H; 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="uz7W6K9H" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E321C2BCAF; Mon, 13 Apr 2026 16:38:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776098331; bh=lIDSzS9EPfSbfpVQdxtZEJ6jAzas17R+pEgeTxxnouE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uz7W6K9Hqlk1fBDnMy++6gcvoMEckT1UP75LlqQBM0eGI/xO6jmWCkOxi87lxGlRU Km3bUHy+hEVblkPaeJYhF0lIESzra+pIjrv5ymJLQlY4FmsiJqJJOa5KP9wSPHzgcF LGfSw5boFFj/y7S/DwV/uZfPJVOhxpdiZXGYeaCY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Ian Abbott Subject: [PATCH 5.15 484/570] comedi: me4000: Fix potential overrun of firmware buffer Date: Mon, 13 Apr 2026 18:00:15 +0200 Message-ID: <20260413155848.588782193@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260413155830.386096114@linuxfoundation.org> References: <20260413155830.386096114@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: Ian Abbott commit 3fb43a7a5b44713f892c58ead2e5f3a1bc9f4ee7 upstream. `me4000_xilinx_download()` loads the firmware that was requested by `request_firmware()`. It is possible for it to overrun the source buffer because it blindly trusts the file format. It reads a data stream length from the first 4 bytes into variable `file_length` and reads the data stream contents of length `file_length` from offset 16 onwards. Add a test to ensure that the supplied firmware is long enough to contain the header and the data stream. On failure, log an error and return `-EINVAL`. Note: The firmware loading was totally broken before commit ac584af59945 ("staging: comedi: me4000: fix firmware downloading"), but that is the most sensible target for this fix. Fixes: ac584af59945 ("staging: comedi: me4000: fix firmware downloading") Cc: stable Signed-off-by: Ian Abbott Link: https://patch.msgid.link/20260205133949.71722-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman --- drivers/comedi/drivers/me4000.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) --- a/drivers/comedi/drivers/me4000.c +++ b/drivers/comedi/drivers/me4000.c @@ -316,6 +316,18 @@ static int me4000_xilinx_download(struct unsigned int val; unsigned int i; + /* Get data stream length from header. */ + if (size >= 4) { + file_length = (((unsigned int)data[0] & 0xff) << 24) + + (((unsigned int)data[1] & 0xff) << 16) + + (((unsigned int)data[2] & 0xff) << 8) + + ((unsigned int)data[3] & 0xff); + } + if (size < 16 || file_length > size - 16) { + dev_err(dev->class_dev, "Firmware length inconsistency\n"); + return -EINVAL; + } + if (!xilinx_iobase) return -ENODEV; @@ -347,10 +359,6 @@ static int me4000_xilinx_download(struct outl(val, devpriv->plx_regbase + PLX9052_CNTRL); /* Download Xilinx firmware */ - file_length = (((unsigned int)data[0] & 0xff) << 24) + - (((unsigned int)data[1] & 0xff) << 16) + - (((unsigned int)data[2] & 0xff) << 8) + - ((unsigned int)data[3] & 0xff); usleep_range(10, 1000); for (i = 0; i < file_length; i++) {