Bug#838913: libc6: There's probably a bug in libpthread, affecting several user programs.

[Fernando Santagata <nando@ipers.net>]

On Tue, Sep 27, 2016 at 01:44:34PM +0200, Florian Weimer wrote:
> * Aurelien Jarno:
> 
> > Hmm, rsync doesn't use libpthread, so that clearly rules out a
> > libpthread issue. That said, all the example you gave fail to allocate
> > the memory correctly, either through malloc (glibc) or mmap (kernel)
> > which returns -ENOMEM. This points to either a kernel issue, or a
> > limitation of the memory using for example ulimit.
> 
> The mm subsystem in the 4.7 upstream kernel has a very visible issue
> which causes allocation failures:
> 
>   <http://marc.info/?l=linux-mm&m=147422898523307>
> 
> There are other threads as well.  (I personally see this with the
> xfs_inode cache.)
> 
> Usually it manifests in premature OOM killer invocations, but maybe
> something the reporter's system configuration changes that (perhaps it
> runs with vm.overcommit_memory=2?).

That's it. I found this in /var/log/kern.log at the time I run a program
that crashed:

Sep 27 10:37:31 gretux kernel: [   77.250470] mmap: moar (2564): VmData 135217152 exceed data ulimit 134217728. Update limits or use boot option ignore_rlimit_data.

Looks like a kernel mmap issue.

-- 
Fernando Santagata