linux-kernel - Re: [PATCH] lib: string_helpers: fix potential snprintf() output truncation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <bb705eb7-c61c-4da9-816e-cbb46c0c16e4@kernel.org>
Date: Tue, 22 Oct 2024 09:15:12 +0200
From: Jiri Slaby <jirislaby@...nel.org>
To: Bartosz Golaszewski <brgl@...ev.pl>, Kees Cook <kees@...nel.org>,
 Andy Shevchenko <andy@...nel.org>, Andrew Morton
 <akpm@...ux-foundation.org>,
 James Bottomley <James.Bottomley@...senPartnership.com>,
 Greg KH <gregkh@...uxfoundation.org>
Cc: linux-hardening@...r.kernel.org, linux-kernel@...r.kernel.org,
 Bartosz Golaszewski <bartosz.golaszewski@...aro.org>, stable@...r.kernel.org
Subject: Re: [PATCH] lib: string_helpers: fix potential snprintf() output
 truncation

On 21. 10. 24, 12:04, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
> 
> The output of ".%03u" with the unsigned int in range [0, 4294966295] may
> get truncated if the target buffer is not 12 bytes.

Perhaps, if you elaborate on how 'remainder' can become > 999?

> Fixes: 3c9f3681d0b4 ("[SCSI] lib: add generic helper to print sizes rounded to the correct SI range")
> Cc: stable@...r.kernel.org
> Reviewed-by: Andy Shevchenko <andy@...nel.org>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
> ---
>   lib/string_helpers.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/string_helpers.c b/lib/string_helpers.c
> index 4f887aa62fa0..91fa37b5c510 100644
> --- a/lib/string_helpers.c
> +++ b/lib/string_helpers.c
> @@ -57,7 +57,7 @@ int string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
>   	static const unsigned int rounding[] = { 500, 50, 5 };
>   	int i = 0, j;
>   	u32 remainder = 0, sf_cap;
> -	char tmp[8];
> +	char tmp[12];
>   	const char *unit;
>   
>   	tmp[0] = '\0';

-- 
js
suse labs