From: ebiederm@xmission•com (Eric W. Biederman)
To: Andrew Morton <akpm@linux-foundation•org>
Cc: Eric Dumazet <eric.dumazet@gmail•com>,
Jiri Slaby <jirislaby@gmail•com>,
linux-kernel@vger•kernel.org, mm-commits@vger•kernel.org,
ML netdev <netdev@vger•kernel.org>,
"David S. Miller" <davem@davemloft•net>
Subject: Re: IPv4: sysctl table check failed [was: mmotm 2010-10-07-14-08 uploaded]
Date: Thu, 07 Oct 2010 17:54:48 -0700 [thread overview]
Message-ID: <m1y6a95wrr.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <20101007152806.119d1522.akpm@linux-foundation.org> (Andrew Morton's message of "Thu, 7 Oct 2010 15:28:06 -0700")
Andrew Morton <akpm@linux-foundation•org> writes:
> On Fri, 08 Oct 2010 00:22:15 +0200
> Eric Dumazet <eric.dumazet@gmail•com> wrote:
>
>> Le vendredi 08 octobre 2010 __ 00:06 +0200, Jiri Slaby a __crit :
>> > On 10/07/2010 11:08 PM, akpm@linux-foundation•org wrote:
>> > > The mm-of-the-moment snapshot 2010-10-07-14-08 has been uploaded to
>> >
>> > Hi, I got bunch of "sysctl table check failed" below. All seem to be
>> > related to ipv4:
>>
>> I would say, sysctl check is buggy :(
>>
>> min/max are optional
>>
>> [PATCH] sysctl: min/max bounds are optional
>>
>> sysctl check complains when proc_doulongvec_minmax or
>> proc_doulongvec_ms_jiffies_minmax are used by a vector of longs (with
>> more than one element), with no min or max value specified.
>>
>> This is unexpected, given we had a bug on this min/max handling :)
>>
>> Reported-by: Jiri Slaby <jirislaby@gmail•com>
>> Signed-off-by: Eric Dumazet <eric.dumazet@gmail•com>
>> ---
>> kernel/sysctl_check.c | 9 ---------
>> 1 file changed, 9 deletions(-)
>>
>> diff --git a/kernel/sysctl_check.c b/kernel/sysctl_check.c
>> index 04cdcf7..10b90d8 100644
>> --- a/kernel/sysctl_check.c
>> +++ b/kernel/sysctl_check.c
>> @@ -143,15 +143,6 @@ int sysctl_check_table(struct nsproxy *namespaces, struct ctl_table *table)
>> if (!table->maxlen)
>> set_fail(&fail, table, "No maxlen");
>> }
>> - if ((table->proc_handler == proc_doulongvec_minmax) ||
>> - (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) {
>> - if (table->maxlen > sizeof (unsigned long)) {
>> - if (!table->extra1)
>> - set_fail(&fail, table, "No min");
>> - if (!table->extra2)
>> - set_fail(&fail, table, "No max");
>> - }
>> - }
>> #ifdef CONFIG_PROC_SYSCTL
>> if (table->procname && !table->proc_handler)
>> set_fail(&fail, table, "No proc_handler");
>
> That will probably fix it ;)
>
> net-avoid-limits-overflow.patch is dependent on this patch. Unless
> Eric B squeaks I'll plan on sending this patch in for 2.6.37.
Oh. I see. I actually had a sanity check for the case that was failing.
I probably spotted the buggy code and wanted to see if there was
anything that cared.
So sysctl_check was perfectly correct until the bug was removed from
proc_doulongvec_minmax. Which also means we have been auditing the
kernel for quite a while to make certain that it is safe not to
increment min and max.
Eric
next prev parent reply other threads:[~2010-10-08 0:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <201010072140.o97Le69i025659@imap1.linux-foundation.org>
2010-10-07 22:06 ` IPv4: sysctl table check failed [was: mmotm 2010-10-07-14-08 uploaded] Jiri Slaby
2010-10-07 22:22 ` Eric Dumazet
2010-10-07 22:28 ` Andrew Morton
2010-10-08 0:54 ` Eric W. Biederman [this message]
2010-10-08 16:30 ` Américo Wang
2010-10-07 22:22 ` Andrew Morton
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