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 EB0E32F25E7; Fri, 5 Dec 2025 18:14:14 +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=1764958455; cv=none; b=uLGNQvagzGICb8X79CDuiZ3dS19Q1GtNkMP06+TWryj0+YGQnffE7knrcnj52aeKSbk7LYKpWQQIQyHMEG1YGiwplpfNm1Tgczx258BdAsDBLNGcXDy/xMyQBq1phfwWQ8XcyJjgF99BmNpUwzyWTyn9YpEKdeBxEIJgP6XeQ4U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764958455; c=relaxed/simple; bh=IC1OejnZkEXWNzAlMQT0aeyZvGu2/TpM7WMNFr1ZJok=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=HbHkg91JkMM3oOfRiEcfmo0WJHOTB0zeeqteaaPPO3vGr/RbK9LHvh6R0G0sZUzpikG74ETE9rBjW15PqyffskpJVK7XUK8fmIJoWIhMbePL7Rf2jAS6UVbupvcNl6sZ01wYsB1YUWR7/w1Jz+BJ9Dt7ikZrE1+Fdf+UjnJMuz0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=e2F3PJ5o; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="e2F3PJ5o" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D30EBC4CEF1; Fri, 5 Dec 2025 18:14:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764958454; bh=IC1OejnZkEXWNzAlMQT0aeyZvGu2/TpM7WMNFr1ZJok=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=e2F3PJ5oMseZBHaaWI6083F2LvTe2UUiJKSk6FKo0bT8Hf9FK2evfCTzdXra6Y4kQ q8l4HxSd+EbJoOI5wAuGgd3xP82dM5fmv7JNHeh6Csrvc9NfImQOaI86OCbrvNpjUr EFwsD1cwOIvNcR6j5YKnOy2be/iD2qwm0V4QOj2qIKncdyKXyh1sUjFVFhoJKlSmnt 8H8L0OlMvGExJFjDg7zyEvWt94MR+Ol9OID8GP1vC0k7UUtaP6dvdFQuto3kuqr9Yz lwJwM+7DdckMVUDHgie6GEeYzYxYxIuE9uTYJ2nD5QFmiuaMWpgTHP4EsviKo8FxqN //a7/38xyCfQA== Message-ID: <9547b5e9-e6e8-4b24-82ac-e38327a54c45@kernel.org> Date: Fri, 5 Dec 2025 12:14:13 -0600 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] wifi: mt76: Fix strscpy buffer overflow in mt76_connac2_load_patch To: Mikhail Gavrilov Cc: Felix Fietkau , Lorenzo Bianconi , linux-wireless@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org References: <20251205161202.48409-1-mikhail.v.gavrilov@gmail.com> Content-Language: en-US From: Mario Limonciello In-Reply-To: <20251205161202.48409-1-mikhail.v.gavrilov@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 12/5/25 10:12 AM, Mikhail Gavrilov wrote: > Commit f804a5895eba ("wifi: mt76: Strip whitespace from build ddate") introduced > a kernel panic/WARN on systems using MediaTek MT7921e (and potentially others > using mt76_connac_lib) due to an incorrect buffer size calculation. > > The error logged is: > "strnlen: detected buffer overflow: 17 byte read of buffer size 16" > > This occurs because the field 'hdr->build_date' is a fixed-size array of 16 bytes. > The patch allocated a 17-byte local buffer 'build_date' but used 'sizeof(build_date)' > (17) as the read limit for strscpy, causing Fortify Source to correctly detect > an attempt to read 17 bytes from the 16-byte source field. > > To fix this, replace strscpy with memcpy, which is appropriate for raw data > copying, and explicitly use the size of the source field (sizeof(hdr->build_date) = 16) > to limit the read, followed by manual null termination. > > Fixes: f804a5895eba ("wifi: mt76: Strip whitespace from build ddate") > Signed-off-by: Mikhail Gavrilov Reviewed-by: Mario Limonciello (AMD) > --- > drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c b/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c > index ea99167765b0..d2c4c65ec464 100644 > --- a/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c > +++ b/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c > @@ -3125,8 +3125,11 @@ int mt76_connac2_load_patch(struct mt76_dev *dev, const char *fw_name) > } > > hdr = (const void *)fw->data; > - strscpy(build_date, hdr->build_date, sizeof(build_date)); > - build_date[16] = '\0'; > + /* hdr->build_date is 16 bytes. Copy exactly 16 bytes to the 17-byte buffer, > + * and then add the null terminator at index 16. > + */ > + memcpy(build_date, hdr->build_date, sizeof(hdr->build_date)); > + build_date[sizeof(hdr->build_date)] = '\0'; > strim(build_date); > dev_info(dev->dev, "HW/SW Version: 0x%x, Build Time: %.16s\n", > be32_to_cpu(hdr->hw_sw_ver), build_date);