netdev - Re: [PATCH] [SCTP] Fix a type cast bug

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] [day] [month] [year] [list]

Message-ID: <482D82A6.1060704@hp.com>
Date:	Fri, 16 May 2008 08:48:38 -0400
From:	Vlad Yasevich <vladislav.yasevich@...com>
To:	Gui Jianfeng <guijianfeng@...fujitsu.com>
Cc:	linux-sctp@...r.kernel.org, David Miller <davem@...emloft.net>,
	netdev <netdev@...r.kernel.org>
Subject: Re: [PATCH] [SCTP] Fix a type cast bug

Gui

Gui Jianfeng wrote:
> Vlad,
> 
> event_arg can never be the type of "struct sctp_chunk *" 
> if the event_type is SCTP_EVENT_T_OTHER. This fix
> prevents from potential kernel crash by some misuse.
> 
> Signed-off-by: Gui Jianfeng <guijianfeng@...fujitsu.com>
> ---
>  net/sctp/sm_sideeffect.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
> index a4763fd..1b4bae9 100644
> --- a/net/sctp/sm_sideeffect.c
> +++ b/net/sctp/sm_sideeffect.c
> @@ -1072,7 +1072,8 @@ static int sctp_cmd_interpreter(sctp_event_t event_type,
>  	struct sctp_sackhdr sackh;
>  	int local_cork = 0;
>  
> -	if (SCTP_EVENT_T_TIMEOUT != event_type)
> +	if (SCTP_EVENT_T_TIMEOUT != event_type &&
> +	    SCTP_EVENT_T_OTHER != event_type)
>  		chunk = (struct sctp_chunk *) event_arg;
>  
>  	/* Note:  This whole file is a huge candidate for rework.


This doesn't really fix the bug since the event_arg can be something else during
primitive events and you would still have a typecast issue.

This code is rather ugly, but if we are going to clean it up, we need to do right
and not band-aid to death.

As it is, NACK on this patch, since it doesn't solve the problem.

-vlad

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html