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 9F3EB23E340; Sat, 13 Dec 2025 02:50:04 +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=1765594209; cv=none; b=WT6PCQPjOUSuYf++22D1cvn9lbuVYkLqI7Hu1VnhgqkeStX+gZ9t+ZV8FFDE1vVHRYeVSFye8k1EreXTXNfJmTDzWUOPnkW/GAbN/4Z5G5iDjYX6INHgFkdWGK9xDv0YEgcuL+vDeRGXQ3D3dE8VwPnew44zlF8+la2jbwaoipc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765594209; c=relaxed/simple; bh=3jOIG/uBAXX9Tf3utTWvIsFwIK6BnzDTtVJEWQ5Bevk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=XHZldFdXty56G9dJ/p5okHK8w/HVk24UlsnVUyl2/ZYeju/qN7S1fDiHeKRyykvMpOJnebrgujAUFXJ5WlY6Bfard0XM9ppDHnBzALorHdDnV+d9fdKrc1Xti7Sem3WSVxYWfGZTA3mceMzHcutE9R+7Ae7uOW8BTKz/f65+jGo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=e9iT+SGl; 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="e9iT+SGl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 59B0AC4CEF1; Sat, 13 Dec 2025 02:50:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1765594204; bh=3jOIG/uBAXX9Tf3utTWvIsFwIK6BnzDTtVJEWQ5Bevk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=e9iT+SGlfCdBnQIerC3vz9B0Sl55FVpjjAxSdcy2rX9+AMzAmMSdsXXALHVqhJvC1 xQqWit5Cuc83HWVa7TWyiM+vctaBtUhhs+rxg/DVnR4e1iesIl/OEZo9L473jwaxzD UqHvownywFDvBuqxP6zI7ArnCiVfVgpiucvDJn6Nr6d92AA7iIb0gCm6fHyqbTRfKy GYaaKNnZAKMBrpI0d/IlFqLJqTFznqHxF7R5BvpJrYon4HimFw9oy2KporchywxMvf p9S6b/xoTKI5oaYOazYl9IR8ieD1Yd18SNz2vMVk8aqLzQ14z30+ch0+fnfK5hDVYv 19qDYUIZnm1bA== Message-ID: <191da5b6-209f-4615-b111-40b98687c705@kernel.org> Date: Fri, 12 Dec 2025 20:50:02 -0600 Precedence: bulk X-Mailing-List: linux-wireless@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: Eric Biggers , 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> <20251213023539.GC71695@sol> Content-Language: en-US From: "Mario Limonciello (AMD) (kernel.org)" In-Reply-To: <20251213023539.GC71695@sol> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 12/12/2025 8:35 PM, Eric Biggers wrote: > On Fri, Dec 05, 2025 at 09:12:02PM +0500, 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 >> --- >> 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); > > Tested-by: Eric Biggers > > Can this be sent upstream soon? > > - Eric Tested-by: Mario Limonciello (AMD)