lkml.org 
[lkml]   [2009]   [Feb]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: Crash (ext3 ) during 2.6.29-rc6 boot
Date
On Thu, 26 Feb 2009 12:31:20 am Geert Uytterhoeven wrote:
> On Wed, 25 Feb 2009, Mark Nelson wrote:
> > On Wed, 25 Feb 2009 08:50:46 pm Geert Uytterhoeven wrote:
> > > On Wed, 25 Feb 2009, Mark Nelson wrote:
> > > > On Tue, 24 Feb 2009 05:38:37 pm Sachin P. Sant wrote:
> > > > > Jan Kara wrote:
> > > > > > Hmm, OK. But then I'm not sure how that can happen. Obviously, memcpy
> > > > > > somehow got beyond end of the page referenced by bh->b_data. So it means
> > > > > > that le16_to_cpu(entry->e_value_offs) + size > page_size. But
> > > > > > ext3_xattr_find_entry() calls ext3_xattr_check_entry() which in
> > > > > > particular checks whether e_value_offs + e_value_size isn't greater than
> > > > > > bh->b_size. So I see no way how memcpy can get beyond end of the page.
> > > > > > Sachin, is the problem reproducible? If yes, can you send us contents
> > > > > >
> > > > > Yes, i am able to recreate this problem easily. As i had mentioned if the
> > > > > earlier kernel is booted with selinux enabled and then 2.6.29-rc6 is booted
> > > > > i get this crash. But if i specify selinux=0 at command line, 2.6.29-rc6 boots
> > > > > without any problem.
> > > >
> > > > Hi Sanchin and Geert,
> > > >
> > > > Does the patch below fix the problems you're seeing? If it does I'll send
> > > > a properly written up and formatted patch to linuxppc-dev (as well as
> > > > another one to fix the same problem in copy_tofrom_user()).
> > >
> > > Unfortunately not, now it crashes while accessing the memory pointed to by
> > > GPR16, in
> > >
> > > NIP: copy_page_range+x0608/0x628
> > > LR: dup_mm+0x2e4/0x428
> > > Trace: debug_table+0xcc70/0x1afe0 (unreliable)
> > > dup_mm+0x2e4/0x428
> > > copy_process+0x86c/0xf9c
> > > do_fork+0x188/0x39c
> > > sys_clone+0x58/0x70
> > > ppc_clone+0x8/0xc
> > >
> > > However, after reverting 25d6e2d7c58ddc4a3b614fc5381591c0cfe66556, I still see
> > > similar problems as above (crash in copy_page_range()).
> > > Which makes me think that
> > > 1. Your new patch fixes the problem introduced by 25d6e2d7,
> > > 2. There's still another issue than the one introduced by 25d6e2d7.
> >
> > Does the following patch fix the errors you're seeing? (it applies the
> > same fix as the previous patch but this time to copy_tofrom_user, which
> > I updated in a4e22f02f5b6518c1484faea1f88d81802b9feac)
>
> Thanks, but I still get crashes in copy_page_range().
>

Hmmm... I'm out of ideas for the moment, but thanks for testing anyway!

Mark


\
 
 \ /
  Last update: 2009-02-25 23:47    [W:0.100 / U:0.360 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site