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From: Pablo Neira Ayuso <pablo@netfilter.org>
To: "Daniel Gröber" <dxld@darkboxed.org>
Cc: netfilter-devel@vger.kernel.org
Subject: Re: [libnf_ct PATCH v2 1/9] Handle negative snprintf return values properly
Date: Wed, 1 Jul 2020 13:09:51 +0200
Message-ID: <20200701110951.GA1346@salvia> (raw)
In-Reply-To: <20200624133005.22046-1-dxld@darkboxed.org>

On Wed, Jun 24, 2020 at 03:29:57PM +0200, Daniel Gröber wrote:
> Currently the BUFFER_SIZE macro doesn't take negative 'ret' values into
> account. A negative return should just be passed through to the caller,
> snprintf will already have set 'errno' properly.

Series applied, thanks.

> diff --git a/include/internal/internal.h b/include/internal/internal.h
> index bb44e12..b1fc670 100644
> --- a/include/internal/internal.h
> +++ b/include/internal/internal.h
> @@ -41,6 +41,8 @@
>  #endif
>  
>  #define BUFFER_SIZE(ret, size, len, offset)		\
> +	if (ret < 0)					\
> +		return -1;				\

Side note: I don't like this hidden branch under a macro. But
snprintf() == -1 is unlikely to happen and I don't have a better idea
to deal with this case ATM.

  parent reply index

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-24 13:29 Daniel Gröber
2020-06-24 13:29 ` [libnf_ct PATCH v2 2/9] Fix nfexp_snprintf return value docs Daniel Gröber
2020-06-24 13:29 ` [libnf_ct PATCH v2 3/9] Replace strncpy with snprintf to improve null byte handling Daniel Gröber
2020-06-24 13:30 ` [libnf_ct PATCH v2 4/9] Fix incorrect snprintf size calculation Daniel Gröber
2020-06-24 13:30 ` [libnf_ct PATCH v2 5/9] Add ARRAY_SIZE() macro Daniel Gröber
2020-06-24 13:30 ` [libnf_ct PATCH v2 6/9] Fix buffer overflow on invalid icmp type in setters Daniel Gröber
2020-06-24 13:30 ` [libnf_ct PATCH v2 7/9] Move icmp request>reply type mapping to common file Daniel Gröber
2020-06-24 13:30 ` [libnf_ct PATCH v2 8/9] Fix buffer overflow in protocol related snprintf functions Daniel Gröber
2020-06-24 13:30 ` [libnf_ct PATCH v2 9/9] Fix buffer overflows in __snprintf_protoinfo* like in *2str fns Daniel Gröber
2020-07-01 11:09 ` Pablo Neira Ayuso [this message]
2020-07-01 13:46   ` [libnf_ct PATCH v2 1/9] Handle negative snprintf return values properly Daniel Gröber

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