[PATCH-stable16] Fix a potential NULL dereference in md/raid1

[PATCH-stable16] Fix a potential NULL dereference in md/raid1

[NeilBrown]

patch for 2.6.16 stable series

My applogies to people reading this with a window narrower than
111 characters :-(

NeilBrown

### Comments for Changeset

At the point where this 'atomic_add' is, rdev could be NULL,
as seen by the fact that we test for this in the very next 
statement.
Further is it is really the wrong place of the add.
We could add to the count of corrected errors 
once the are sure it was corrected, not before
trying to correct it.

Signed-off-by: Neil Brown <neilb@suse.de>

### Diffstat output
 ./drivers/md/raid1.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff .prev/drivers/md/raid1.c ./drivers/md/raid1.c
--- .prev/drivers/md/raid1.c	2006-08-21 09:47:57.000000000 +1000
+++ ./drivers/md/raid1.c	2006-08-21 09:43:37.000000000 +1000
@@ -1467,7 +1467,6 @@ static void raid1d(mddev_t *mddev)
 							d = conf->raid_disks;
 						d--;
 						rdev = conf->mirrors[d].rdev;
-						atomic_add(s, &rdev->corrected_errors);
 						if (rdev &&
 						    test_bit(In_sync, &rdev->flags)) {
 							if (sync_page_io(rdev->bdev,
@@ -1490,6 +1489,9 @@ static void raid1d(mddev_t *mddev)
 									 s<<9, conf->tmppage, READ) == 0)
 								/* Well, this device is dead */
 								md_error(mddev, rdev);
+							else
+								atomic_add(s, &rdev->corrected_errors);
+
 						}
 					}
 				} else {

Re: [PATCH-stable16] Fix a potential NULL dereference in md/raid1

[Adrian Bunk]

On Mon, Aug 21, 2006 at 09:50:13AM +1000, NeilBrown wrote:

> patch for 2.6.16 stable series
>...

Thanks for this patch.

It does also apply against both 2.6.17.9 and Linus' tree.

Is it not required in these trees, or are you also submitting it there?

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [PATCH-stable16] Fix a potential NULL dereference in md/raid1

[Neil Brown]

On Monday August 21, bunk@stusta.de wrote:
> On Mon, Aug 21, 2006 at 09:50:13AM +1000, NeilBrown wrote:
> 
> > patch for 2.6.16 stable series
> >...
> 
> Thanks for this patch.
> 
> It does also apply against both 2.6.17.9 and Linus' tree.
> 
> Is it not required in these trees, or are you also submitting it there?

I've just sent a patch to stable@kernel.org for 2.6.17.9. (it is the
same patch with slightly different line numbers).

The patch for -linus is quite different and will follow shortly (with
a few other patches).

Thanks,
NeilBrown

Re: [PATCH-stable16] Fix a potential NULL dereference in md/raid1

[Adrian Bunk]

On Mon, Aug 21, 2006 at 10:07:12AM +1000, Neil Brown wrote:
> On Monday August 21, bunk@stusta.de wrote:
> > On Mon, Aug 21, 2006 at 09:50:13AM +1000, NeilBrown wrote:
> > 
> > > patch for 2.6.16 stable series
> > >...
> > 
> > Thanks for this patch.
> > 
> > It does also apply against both 2.6.17.9 and Linus' tree.
> > 
> > Is it not required in these trees, or are you also submitting it there?
> 
> I've just sent a patch to stable@kernel.org for 2.6.17.9. (it is the
> same patch with slightly different line numbers).
> 
> The patch for -linus is quite different and will follow shortly (with
> a few other patches).

OK, I'll apply this patch when it has successfully passed 2.6.17 review 
and got included in 2.6.17.

> Thanks,
> NeilBrown

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [PATCH-stable16] Fix a potential NULL dereference in md/raid1

[Adrian Bunk]

On Mon, Aug 21, 2006 at 02:28:47AM +0200, Adrian Bunk wrote:
> On Mon, Aug 21, 2006 at 10:07:12AM +1000, Neil Brown wrote:
> > On Monday August 21, bunk@stusta.de wrote:
> > > On Mon, Aug 21, 2006 at 09:50:13AM +1000, NeilBrown wrote:
> > > 
> > > > patch for 2.6.16 stable series
> > > >...
> > > 
> > > Thanks for this patch.
> > > 
> > > It does also apply against both 2.6.17.9 and Linus' tree.
> > > 
> > > Is it not required in these trees, or are you also submitting it there?
> > 
> > I've just sent a patch to stable@kernel.org for 2.6.17.9. (it is the
> > same patch with slightly different line numbers).
> > 
> > The patch for -linus is quite different and will follow shortly (with
> > a few other patches).
> 
> OK, I'll apply this patch when it has successfully passed 2.6.17 review 
> and got included in 2.6.17.

Applied, thanks for the patch.

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed