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From: Florian Westphal <fw@strlen.de>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: netfilter-devel@vger.kernel.org
Subject: panic_on_warn and lack of lesser-WARN  (was: Re: [PATCH nf] netfilter: nf_nat: do not reuse an unexpected expectation on RTCP clash)
Date: Sun, 12 Jul 2026 10:40:47 +0200	[thread overview]
Message-ID: <alNTD-kTq6svigxI@strlen.de> (raw)
In-Reply-To: <2026071210-grid-runaround-4318@gregkh>

Greg KH <gregkh@linuxfoundation.org> wrote:
> > > True, but adding new ones is not a good idea, and removing the existing
> > > ones is a good idea.
> > 
> > We're fucked, then.  Can we at least use DEBUG_NET_WARN or something
> > like that so at least fizzers can give us hints about bugs?!
> 
> That's up to you.  If panic_on_warn wasn't an option, about half of the
> kernel CVEs would disappear tomorrow.

That explains your WARN() allergy, I can relate to that.

Its a shame there is nothing like WARN_BENIGN() or similar that doesn't
panic even with panic_on_warn=1.

I get some people really want s/WARN/BUG at run time for things
like "this list is corrupted" or "you tried refcount_inc() on a 0
refcount".  But even for "this refcount is saturated" I don't get
why you want to crash the system right away.

Feels a bit like setting your car on fire because the side window was
slightly dirty :-)

      reply	other threads:[~2026-07-12  8:40 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-10 23:19 netfilter: nf_nat_sip expectation UAF permits local privilege escalation Jaeyeong Lee
2026-07-11  5:29 ` Greg KH
2026-07-11 14:21   ` [PATCH nf] netfilter: nf_nat: do not reuse an unexpected expectation on RTCP clash Jaeyeong Lee
2026-07-11 16:29     ` Florian Westphal
2026-07-12  5:54       ` Greg KH
2026-07-12  7:40         ` Florian Westphal
2026-07-12  7:54           ` Greg KH
2026-07-12  8:08             ` Florian Westphal
2026-07-12  8:20               ` Greg KH
2026-07-12  8:40                 ` Florian Westphal [this message]

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