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 2AC35332628; Fri, 29 May 2026 07:20:56 +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=1780039258; cv=none; b=Xgc9pjS9zg6VtHLqiFhLcyxpgkLnEQ7M6NzBxhPzhqZ95tkBy9ZrQczbQrSvSPhh2c4CQPvsVIeuiq6J2zlbIB6ULJ1romK3pox6lbI3Sv+wuXUl30aO7bKMlZSdd4v7P1kx5klXc3PaRUfxPhNcZcwotl1vnshAZe6mR9ksixk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780039258; c=relaxed/simple; bh=MrkEv9oGgPOTopvm1MDPEEeE60MC9cJMiwLFsfcHArc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=CFEknEnf4nRrHgmnHrW5BXJo6H/QfMzG7Unjj0ciZ+xMu/i6Nt4zSdXeoU3zV6M/G3CZZl+Nykn7E6CI+Iz4LIFSrTuDiCyI+AjBQ0kd3iizYdcBoGDk6E4XXL70aVPSb/aNFZzxNXzqDpm3FqjqtspzohHMYe0eyHX7oWk8Rn8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kmcmORvh; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kmcmORvh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B93B1F00893; Fri, 29 May 2026 07:20:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780039256; bh=qOHmKFTXw2FsM+mZsbVdA3Sg5+qsZZkc2PbmdG0maa8=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=kmcmORvhLRh8u6t6mtYBJcufHVzzJGbix+rX++Im+8TDMMf64rB9neDYXPtSFT4zF YnyeqhRU1XZZ+Z/xij0T1D0/SwZ4TzU61AvP3U9GcwvzEKaV0vxscgQFB0OmDl07Pn 3+OE2Hef7CVAMuJfLEV8DF/JPXFTw4W8rzGEqhUr39eEvq+hWpRGPFBHN7qyUlPSvM N7yL7evYZUZzW/new6TuZKj4uPA/VPznt/Mtu2++w58kRssnBg3HpyMD4/j24UASo4 7FcUvwKj9O+F8DUYuZdT8vbtfp/z3XE+E46ewEpAPsQ6ROSfofMrawcDtBG7d6aBKY epMde6x2ERtRw== Message-ID: <405e97ae-72a1-4086-bef3-cf462619f661@kernel.org> Date: Fri, 29 May 2026 09:20:53 +0200 Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] ACPICA: Replace strncpy() with strscpy_pad() in acpi_ut_safe_strncpy() To: "Rafael J. Wysocki" , Kees Cook Cc: Robert Moore , Len Brown , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, acpica-devel@lists.linux.dev, linux-hardening@vger.kernel.org References: <20260323172451.work.079-kees@kernel.org> Content-Language: en-US From: Jiri Slaby Autocrypt: addr=jirislaby@kernel.org; keydata= xsFNBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABzSFKaXJpIFNsYWJ5 IDxqaXJpc2xhYnlAa2VybmVsLm9yZz7CwXcEEwEIACEFAlW3RUwCGwMFCwkIBwIGFQgJCgsC BBYCAwECHgECF4AACgkQvSWxBAa0cEnVTg//TQpdIAr8Tn0VAeUjdVIH9XCFw+cPSU+zMSCH eCZoA/N6gitEcnvHoFVVM7b3hK2HgoFUNbmYC0RdcSc80pOF5gCnACSP9XWHGWzeKCARRcQR 4s5YD8I4VV5hqXcKo2DFAtIOVbHDW+0okOzcecdasCakUTr7s2fXz97uuoc2gIBB7bmHUGAH XQXHvdnCLjDjR+eJN+zrtbqZKYSfj89s/ZHn5Slug6w8qOPT1sVNGG+eWPlc5s7XYhT9z66E l5C0rG35JE4PhC+tl7BaE5IwjJlBMHf/cMJxNHAYoQ1hWQCKOfMDQ6bsEr++kGUCbHkrEFwD UVA72iLnnnlZCMevwE4hc0zVhseWhPc/KMYObU1sDGqaCesRLkE3tiE7X2cikmj/qH0CoMWe gjnwnQ2qVJcaPSzJ4QITvchEQ+tbuVAyvn9H+9MkdT7b7b2OaqYsUP8rn/2k1Td5zknUz7iF oJ0Z9wPTl6tDfF8phaMIPISYrhceVOIoL+rWfaikhBulZTIT5ihieY9nQOw6vhOfWkYvv0Dl o4GRnb2ybPQpfEs7WtetOsUgiUbfljTgILFw3CsPW8JESOGQc0Pv8ieznIighqPPFz9g+zSu Ss/rpcsqag5n9rQp/H3WW5zKUpeYcKGaPDp/vSUovMcjp8USIhzBBrmI7UWAtuedG9prjqfO wU0ETpLnhgEQAM+cDWLL+Wvc9cLhA2OXZ/gMmu7NbYKjfth1UyOuBd5emIO+d4RfFM02XFTI t4MxwhAryhsKQQcA4iQNldkbyeviYrPKWjLTjRXT5cD2lpWzr+Jx7mX7InV5JOz1Qq+P+nJW YIBjUKhI03ux89p58CYil24Zpyn2F5cX7U+inY8lJIBwLPBnc9Z0An/DVnUOD+0wIcYVnZAK DiIXODkGqTg3fhZwbbi+KAhtHPFM2fGw2VTUf62IHzV+eBSnamzPOBc1XsJYKRo3FHNeLuS8 f4wUe7bWb9O66PPFK/RkeqNX6akkFBf9VfrZ1rTEKAyJ2uqf1EI1olYnENk4+00IBa+BavGQ 8UW9dGW3nbPrfuOV5UUvbnsSQwj67pSdrBQqilr5N/5H9z7VCDQ0dhuJNtvDSlTf2iUFBqgk 3smln31PUYiVPrMP0V4ja0i9qtO/TB01rTfTyXTRtqz53qO5dGsYiliJO5aUmh8swVpotgK4 /57h3zGsaXO9PGgnnAdqeKVITaFTLY1ISg+Ptb4KoliiOjrBMmQUSJVtkUXMrCMCeuPDGHo7 39Xc75lcHlGuM3yEB//htKjyprbLeLf1y4xPyTeeF5zg/0ztRZNKZicgEmxyUNBHHnBKHQxz 1j+mzH0HjZZtXjGu2KLJ18G07q0fpz2ZPk2D53Ww39VNI/J9ABEBAAHCwV8EGAECAAkFAk6S 54YCGwwACgkQvSWxBAa0cEk3tRAAgO+DFpbyIa4RlnfpcW17AfnpZi9VR5+zr496n2jH/1ld wRO/S+QNSA8qdABqMb9WI4BNaoANgcg0AS429Mq0taaWKkAjkkGAT7mD1Q5PiLr06Y/+Kzdr 90eUVneqM2TUQQbK+Kh7JwmGVrRGNqQrDk+gRNvKnGwFNeTkTKtJ0P8jYd7P1gZb9Fwj9YLx jhn/sVIhNmEBLBoI7PL+9fbILqJPHgAwW35rpnq4f/EYTykbk1sa13Tav6btJ+4QOgbcezWI wZ5w/JVfEJW9JXp3BFAVzRQ5nVrrLDAJZ8Y5ioWcm99JtSIIxXxt9FJaGc1Bgsi5K/+dyTKL wLMJgiBzbVx8G+fCJJ9YtlNOPWhbKPlrQ8+AY52Aagi9WNhe6XfJdh5g6ptiOILm330mkR4g W6nEgZVyIyTq3ekOuruftWL99qpP5zi+eNrMmLRQx9iecDNgFr342R9bTDlb1TLuRb+/tJ98 f/bIWIr0cqQmqQ33FgRhrG1+Xml6UXyJ2jExmlO8JljuOGeXYh6ZkIEyzqzffzBLXZCujlYQ DFXpyMNVJ2ZwPmX2mWEoYuaBU0JN7wM+/zWgOf2zRwhEuD3A2cO2PxoiIfyUEfB9SSmffaK/ S4xXoB6wvGENZ85Hg37C7WDNdaAt6Xh2uQIly5grkgvWppkNy4ZHxE+jeNsU7tg= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 23. 03. 26, 18:31, Rafael J. Wysocki wrote: > On Mon, Mar 23, 2026 at 6:24 PM Kees Cook wrote: >> >> Replace the deprecated[1] strncpy() with strscpy_pad() in >> acpi_ut_safe_strncpy(). >> >> The function is a "safe strncpy" wrapper that does >> strncpy(dest, source, dest_size) followed by manual NUL-termination >> at dest[dest_size - 1]. strscpy_pad() is a direct replacement: it >> NUL-terminates, zero-pads the remainder, and the manual termination >> is no longer needed. >> >> All callers pass NUL-terminated source strings (C string literals, >> __FILE__ via ACPI_MODULE_NAME, or user-provided filenames that have >> already been validated). The destinations are fixed-size char arrays >> in ACPICA internal structures (allocation->module, aml_op_name, >> acpi_gbl_db_debug_filename), all consumed as C strings. >> >> No behavioral change: strscpy_pad() produces identical output to >> strncpy() + manual NUL-termination for NUL-terminated sources that >> are shorter than dest_size. For sources longer than dest_size, >> strncpy() wrote dest_size non-NUL bytes then the manual termination >> overwrote the last byte with NUL; strscpy_pad() writes dest_size-1 >> bytes plus NUL: same result. >> >> Link: https://github.com/KSPP/linux/issues/90 [1] >> Signed-off-by: Kees Cook >> --- >> This touches the ACPICA component shared with the upstream ACPICA >> project (https://github.com/acpica/acpica), where the function >> is named AcpiUtSafeStrncpy(). The upstream codebase uses its own >> platform abstraction layer (acenv.h/acgcc.h) where I've mapped various >> kernel APIs before like ACPI_FLEX_ARRAY and similar helpers. However, >> acpi_ut_safe_strncpy() is an explicit function implementation rather >> than a macro mapping, so the approach for upstreaming this change to >> ACPICA is not clear. What's the best way to land this? > > I can apply this directly, it shouldn't be a major problem for porting > patches from the upstream. As I reported in https://github.com/acpica/acpica/issues/1158 (but got no reply), this patch breaks build of acpica against 7.1-rc*: > ../../../../../drivers/acpi/acpica/utnonansi.c:171:9: error: implicit declaration of function ‘strscpy_pad’ [-Wimplicit-function-declaration] Is strscpy_pad() supposed to be emulated in acpica? >> (This is one of the last users of strncpy in the kernel.) >> --- >> drivers/acpi/acpica/utnonansi.c | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/drivers/acpi/acpica/utnonansi.c b/drivers/acpi/acpica/utnonansi.c >> index ff0802ace19b..3a7952be6545 100644 >> --- a/drivers/acpi/acpica/utnonansi.c >> +++ b/drivers/acpi/acpica/utnonansi.c >> @@ -168,8 +168,7 @@ void acpi_ut_safe_strncpy(char *dest, char *source, acpi_size dest_size) >> { >> /* Always terminate destination string */ >> >> - strncpy(dest, source, dest_size); >> - dest[dest_size - 1] = 0; >> + strscpy_pad(dest, source, dest_size); >> } >> >> #endif >> -- > thanks, -- js suse labs