netdev - Re: [BUG] net_cls: Panic occured when net

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: <1243686683.3966.117.camel@dogo.mojatatu.com>
Date:	Sat, 30 May 2009 08:31:23 -0400
From:	jamal <hadi@...erus.ca>
To:	Jarek Poplawski <jarkao2@...il.com>
Cc:	Minoru Usui <mi.usui@...il.com>,
	Minoru Usui <usui@....nes.nec.co.jp>, netdev@...r.kernel.org,
	containers@...ts.linux-foundation.org
Subject: Re: [BUG] net_cls: Panic occured when net_cls subsystem use

On Sat, 2009-05-30 at 14:07 +0200, Jarek Poplawski wrote:
> On Sat, May 30, 2009 at 07:56:34AM -0400, jamal wrote:

> > tp_created is the check
> > n->nlmsg_type == RTM_NEWTFILTER && n->nlmsg_flags&NLM_F_CREATE
> > replace will be
> > n->nlmsg_type == RTM_NEWTFILTER && n->nlmsg_flags & NLM_F_EXCL
> 
> Hmm... Probably I miss something, but I've just seen this prink during
> tc filter replace with:
> 
> err = tp->ops->change();
> if (n->nlmsg_type == RTM_NEWTFILTER && (n->nlmsg_flags&NLM_F_CREATE))
> 	printk(...);

That sounds right. 
Remeber, you could have NLM_F_EXCL|NLM_F_CREATE to indicate "create this
thing if it doesnt exist; if it exists  it is an error"
If it doesnt exist we will enter that (tp == NULL) path
also fh will be 0 ==> So you will never enter the code
path you are refering to.
If it exists (i.e you found it) and you enter the code path you refer
to, then you surely dont want to destroy it if NLM_F_EXCL is set.

> > I think they are two separate issues.
> > The fact that we dont destroy an allocated tp on failure is an issue
> > regardless of what cls_group does. In the case of Minoru's issue
> > it is because he is misconfiguring cls_group.
> 
> Sure, but we don't want people to get oops in such a case, I guess.
> 

The ops is caused by the code fixed in the patch - did i miss something?

cheers,
jamal

--
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