Re: linux-next 20141216 BUG: sleeping function called from invalid context at mm/slab.c:2849
On Thu, 2014-12-18 at 12:46 -0500, Richard Guy Briggs wrote:
On 14/12/18, Eric Paris wrote:
> On Thu, 2014-12-18 at 11:45 -0500, Valdis.Kletnieks(a)vt.edu wrote:
> > On Tue, 16 Dec 2014 20:09:54 -0500, Valdis Kletnieks said:
> > > Spotted these two while booting single-user on 20141216. 20141208
> > > doesn't throw these, so it's something in the last week or so..
> >
> > Gaah! Turns out that 20141208 *is* susceptible - it had been booting
> > just fine for several days, but it went around the bend, apparently due
> > to a userspace or initrd change.
>
> $5 says you updated systemd?
>
> Richard?
Ok, so if you are correct, then either we justify dropping the lock (I
assume the one commone to both BUG reports [sig->cred_guard_mutex] ),
or we make yet another queue were were hoping to avoid...
It would also be good to narrow it down to a rule that triggers this.
I thought the first message was enough to find the problem, but:
static void kauditd_send_multicast_skb(struct sk_buff *skb)
{
...
nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL);
...
}
Since kauditd_send_multicast_skb() gets called in audit_log_end(), which
can come from any context (aka even a sleeping context) you can't use
GFP_KERNEL. The audit_buffer know what context it should use. So pass
that down and use that.
-Eric
> > egrep 'BUG|Linux vers' from my syslog:
> >
> > Dec 9 12:19:53 turing-police kernel: [ 0.000000] Linux version
3.18.0-next-20141208 (source(a)turing-police.cc.vt.edu) (gcc version 4.9.2 20141101 (Red Hat
4.9.2-1) (GCC) ) #27 SMP PREEMPT Mon Dec 8 22:20:07 EST 2014
...
> > Dec 12 19:42:30 turing-police kernel: [ 0.000000] Linux version
3.18.0-next-20141208 (source(a)turing-police.cc.vt.edu) (gcc version 4.9.2 20141101 (Red Hat
4.9.2-1) (GCC) ) #27 SMP PREEMPT Mon Dec 8 22:20:07 EST 2014
> > Dec 12 20:00:39 turing-police kernel: [ 1109.635328] BUG: sleeping function
called from invalid context at mm/slab.c:2849
...
> > Dec 12 20:42:47 turing-police kernel: [ 3633.863552] BUG: sleeping function
called from invalid context at mm/slab.c:2849
> > Dec 12 20:51:33 turing-police kernel: [ 0.000000] Linux version
3.18.0-next-20141208 (source(a)turing-police.cc.vt.edu) (gcc version 4.9.2 20141101 (Red Hat
4.9.2-1) (GCC) ) #27 SMP PREEMPT Mon Dec 8 22:20:07 EST 2014
> > Dec 12 21:51:04 turing-police kernel: [ 3587.132867] BUG: sleeping function
called from invalid context at mm/slab.c:2849
...
> > I need to figure out what changed around 7:30PM on the 12th.
- RGB
--
Richard Guy Briggs <rbriggs(a)redhat.com>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
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