Messages in this thread | | | From | (Eric W. Biederman) | Date | Thu, 07 Oct 2010 17:54:48 -0700 | Subject | Re: IPv4: sysctl table check failed [was: mmotm 2010-10-07-14-08 uploaded] |
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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
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