Re: 2.6.31-rc2: BUG: unable to handle kernel NULL pointer dereference

[Thomas Meyer <thomas@m3y3r.de>]

Am Sonntag, den 12.07.2009, 22:26 +0200 schrieb Jiri Slaby:
> On 07/12/2009 07:30 PM, Parag Warudkar wrote:
> > static void selinux_write_opts(struct seq_file *m,
> > 1012                                struct security_mnt_opts *opts)
> > 1013 {
> > 1014         int i;
> > 1015         char *prefix;
> > 1016
> > 1017         for (i = 0; i < opts->num_mnt_opts; i++) {
> > 1018                 char *has_comma;
> > 1019
> > 1020                 if (opts->mnt_opts[i])
> > 1021                         has_comma = strchr(opts->mnt_opts[i], ',');
> >                                          ^^^^^^^^^^^^^^^^^^^^^^^^^
> > And that is a NULL pointer dereference - but we just checked for
> > opts->mnt_opts[i] for not NULL. 
> 
> Note, that there is not a NULL dereference. It dereferences 0x40 which
> came in as %rdi. Looks like somebody assigned garbage in there.
> 
> Or a single bit mem error. Is memtest OK with this machine?
Yes it ran fine for one cycle (about 2:15 hours).

Maybe memory in acpi S3 is not so stable? Is this possible?

> 
> What warning tainted the kernel before this oops is still interesting...