NetBSD Problem Report #39292

From hrosenfe@osrc91.amd.com  Tue Aug  5 12:19:50 2008
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Date: Tue, 5 Aug 2008 13:19:04 +0200
From: <hans.rosenfeld@grumpf.hope-2000.org>
Reply-To: hrosenfe@osrc91.amd.com
To: gnats-bugs@gnats.NetBSD.org
Subject: dhclient running amok, sending hundreds of requests per second
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>Number:         39292
>Category:       bin
>Synopsis:       dhclient running amok, sending hundreds of requests per second
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    bin-bug-people
>State:          closed
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Aug 05 12:20:00 +0000 2008
>Closed-Date:    Sun Jan 06 02:03:35 +0000 2019
>Last-Modified:  Sun Jan 06 02:03:35 +0000 2019
>Originator:     Hans Rosenfeld
>Release:        NetBSD 4.0_STABLE
>Organization:
>Environment:
System: NetBSD escobedo 4.0_STABLE NetBSD 4.0_STABLE (ESCOBEDO) #5: Mon Feb 11 21:13:51 CET 2008 hrosenfe@escobedo:/usr/src/sys/arch/amd64/compile/ESCOBEDO amd64
Architecture: x86_64
Machine: amd64
>Description:
dhclient suddenly started looping, sending out requests as fast as it
could. It logged thousands of messages just like these:

Aug  3 19:31:25 escobedo dhclient: DHCPDISCOVER on ex0 to 255.255.255.255 port 67 interval 4
Aug  3 19:31:25 escobedo dhclient: DHCPOFFER from xx.xx.xx.xx
Aug  3 19:31:25 escobedo dhclient: DHCPREQUEST on ex0 to 255.255.255.255 port 67
Aug  3 19:31:25 escobedo dhclient: DHCPACK from xx.xx.xx.xx
Aug  3 19:31:25 escobedo dhclient: /home/builds/ab/netbsd-4-0-RELEASE/src/dist/dhcp/client/dhclient.c(2072): null pointer
Aug  3 19:31:25 escobedo dhclient: DHCPDECLINE on ex0 to 255.255.255.255 port 67
Aug  3 19:31:25 escobedo dhclient: DHCPDISCOVER on ex0 to 255.255.255.255 port 67 interval 7
Aug  3 19:31:25 escobedo dhclient: DHCPOFFER from xx.xx.xx.xx
Aug  3 19:31:25 escobedo dhclient: DHCPREQUEST on ex0 to 255.255.255.255 port 67
Aug  3 19:31:25 escobedo dhclient: DHCPACK from xx.xx.xx.xx
Aug  3 19:31:25 escobedo dhclient: /home/builds/ab/netbsd-4-0-RELEASE/src/dist/dhcp/client/dhclient.c(2072): null pointer
Aug  3 19:31:25 escobedo dhclient: DHCPDECLINE on ex0 to 255.255.255.255 port 67

>How-To-Repeat:
Before dhclient began acting strange, amd(8) segfaulted and filled /
with a coredump. After a while there were enough processes hanging in
NFS accesses that no more forking was possible. The dhclient loop then
caused /var to fill up too, not only on this machine but also on the
dhcp server.

I don't know exactly what caused this behaviour, but I think it is
related to the execution of a script failing in bind_lease. The error
occured in make_decline, which is only called from bind_lease and only
if the script execution fails.

>Fix:
I looked at the dhclient code, but I have no idea where to fix it. The
error is logged in option_state_dereference (dist/dhcp/common/alloc.c:926), 
but it is subsequently ignored, so dhclient just tries again.


>Release-Note:

>Audit-Trail:

State-Changed-From-To: open->feedback
State-Changed-By: gutteridge@NetBSD.org
State-Changed-When: Sun, 23 Dec 2018 01:50:09 +0000
State-Changed-Why:
dhclient has been superseded by dhcpcd. Is this still a concern?

State-Changed-From-To: feedback->closed
State-Changed-By: gutteridge@NetBSD.org
State-Changed-When: Sun, 06 Jan 2019 02:03:35 +0000
State-Changed-Why:
Submitter's email bounced. Stale PR for deprecated tool.

>Unformatted:

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