Bug #948

netstat patch

Added by jschauma about 6 years ago. Updated over 1 year ago.

Status:ClosedStart date:
Priority:NormalDue date:
Assignee:sepherosa% Done:

0%

Category:-
Target version:-

Description

Hello,

There is a bug in netstat(1) that can cause it to spin out of control
and eat up all CPU. This has been reported in FreeBSD and NetBSD and
I've also seen reports of the same problem in Mac OS X, so it stands to
reason this might affect DragonFlyBSD as well.

John Baldwin fixed this in FreeBSD:
http://www.freebsd.org/cgi/cvsweb.cgi/src/usr.bin/netstat/route.c.diff?r1=1.87;r2=1.88

"Make netstat -rn more resilient to having the routing table change out
from
under it while running. Note that this is still not perfect:
- Try to do something intelligent if kvm_read() fails to read a routing
table structure such as an rtentry, radix_node, or ifnet.
- Don't follow left and right node pointers in radix_nodes unless
RNF_ACTIVE is set in rn_flags. This avoids walking through freed
radix_nodes."

The NetBSD error report is at
http://www.netbsd.org/cgi-bin/query-pr-single.pl?number=36195

-Jan

History

#1 Updated by gstanley almost 6 years ago

Does this bug effect you, or have you encountered this bug on Dfly?

#2 Updated by jschauma almost 6 years ago

Gary Stanley <> wrote:

I don't use DragonFlyBSD, so it has not affected me. I just filed the
bug based on the assumption that all BSDs were affected. If you
conclude that Dfly is not affected, feel free to close this.

-Jan

#3 Updated by sepherosa almost 5 years ago

Grab. The patch looks good.

#4 Updated by marino over 1 year ago

  • Description updated (diff)
  • Assignee set to sepherosa

Sephe, I don't think this patch was ever incorporated. I looked in gitweb.
Is this still valid?

#5 Updated by sepherosa over 1 year ago

On Thu, Nov 15, 2012 at 10:28 PM, John Marino via Redmine
<> wrote:
>
> Issue #948 has been updated by John Marino.
>
> Description updated
> Assignee set to Sepherosa Ziehau
>
> Sephe, I don't think this patch was ever incorporated. I looked in gitweb.
> Is this still valid?

Patch committed:
0e23ab10e5db9a505c79ad0f5972c2740ddd3341

> ----------------------------------------
> Bug #948: netstat patch
> http://bugs.dragonflybsd.org/issues/948
>
> Author: Jan Schaumann
> Status: New
> Priority: Normal
> Assignee: Sepherosa Ziehau
> Category:
> Target version:
>
>
> Hello,
>
> There is a bug in netstat(1) that can cause it to spin out of control
> and eat up all CPU. This has been reported in FreeBSD and NetBSD and
> I've also seen reports of the same problem in Mac OS X, so it stands to
> reason this might affect DragonFlyBSD as well.
>
> John Baldwin fixed this in FreeBSD:
> http://www.freebsd.org/cgi/cvsweb.cgi/src/usr.bin/netstat/route.c.diff?r1=1.87;r2=1.88
>
> "Make netstat -rn more resilient to having the routing table change out
> from
> under it while running. Note that this is still not perfect:
> - Try to do something intelligent if kvm_read() fails to read a routing
> table structure such as an rtentry, radix_node, or ifnet.
> - Don't follow left and right node pointers in radix_nodes unless
> RNF_ACTIVE is set in rn_flags. This avoids walking through freed
> radix_nodes."
>
> The NetBSD error report is at
> http://www.netbsd.org/cgi-bin/query-pr-single.pl?number=36195
>
> -Jan
>
>
> --
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--
Tomorrow Will Never Die

#6 Updated by marino over 1 year ago

  • Status changed from New to Closed

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