diff mbox series

[SRU,K:master-next,v2,2/2] pktcdvd: check for NULL returna fter calling bio_split_to_limits()

Message ID 20230601082705.102124-3-aleksandr.mikhalitsyn@canonical.com
State New
Headers show
Series fix bio_split_to_limits() NULL pointer dereference | expand

Commit Message

Aleksandr Mikhalitsyn June 1, 2023, 8:27 a.m. UTC 
From: Jens Axboe <axboe@kernel.dk>

BugLink: https://bugs.launchpad.net/bugs/2020901

commit 3e9900f3bd7ba30d60f82b162b70a1dffe4e8e24 upstream.

The revert of the removal of this driver happened after we fixed up
the split limits for NOWAIT issue, hence it got missed. Ensure that
we check for a NULL bio after splitting, in case it should be retried.

Marking this as fixing both commits, so that stable backport will do
this correctly.

Cc: stable@vger.kernel.org
Fixes: 9cea62b2cbab ("block: don't allow splitting of a REQ_NOWAIT bio")
Fixes: 4b83e99ee709 ("Revert "pktcdvd: remove driver."")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[amikhalitsyn: adjust context bio_split_to_limits -> blk_queue_split]
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
---
 drivers/block/pktcdvd.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Andrea Righi June 1, 2023, 8:56 a.m. UTC | #1 
On Thu, Jun 01, 2023 at 10:27:05AM +0200, Alexander Mikhalitsyn wrote:
> From: Jens Axboe <axboe@kernel.dk>
> 
> BugLink: https://bugs.launchpad.net/bugs/2020901

Is this a private bug? I can't see it.

> 
> commit 3e9900f3bd7ba30d60f82b162b70a1dffe4e8e24 upstream.

^ You can drop this line, see below.

> 
> The revert of the removal of this driver happened after we fixed up
> the split limits for NOWAIT issue, hence it got missed. Ensure that
> we check for a NULL bio after splitting, in case it should be retried.
> 
> Marking this as fixing both commits, so that stable backport will do
> this correctly.
> 
> Cc: stable@vger.kernel.org
> Fixes: 9cea62b2cbab ("block: don't allow splitting of a REQ_NOWAIT bio")
> Fixes: 4b83e99ee709 ("Revert "pktcdvd: remove driver."")
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> [amikhalitsyn: adjust context bio_split_to_limits -> blk_queue_split]

The proper syntax here would be:

(backported from 3e9900f3bd7ba30d60f82b162b70a1dffe4e8e24)
[amikhalitsyn: adjust context bio_split_to_limits -> blk_queue_split]

Or if you don't have to do any change (or very minimal changes):

(cherry-picked from 3e9900f3bd7ba30d60f82b162b70a1dffe4e8e24)

> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
> ---

-Andrea
Aleksandr Mikhalitsyn June 1, 2023, 9:42 a.m. UTC | #2 
On Thu, Jun 1, 2023 at 10:56 AM Andrea Righi <andrea.righi@canonical.com> wrote:
>
> On Thu, Jun 01, 2023 at 10:27:05AM +0200, Alexander Mikhalitsyn wrote:
> > From: Jens Axboe <axboe@kernel.dk>
> >
> > BugLink: https://bugs.launchpad.net/bugs/2020901
>
> Is this a private bug? I can't see it.

Ah, yep. We've decided to make it public.

>
> >
> > commit 3e9900f3bd7ba30d60f82b162b70a1dffe4e8e24 upstream.
>
> ^ You can drop this line, see below.

Fixed.

>
> >
> > The revert of the removal of this driver happened after we fixed up
> > the split limits for NOWAIT issue, hence it got missed. Ensure that
> > we check for a NULL bio after splitting, in case it should be retried.
> >
> > Marking this as fixing both commits, so that stable backport will do
> > this correctly.
> >
> > Cc: stable@vger.kernel.org
> > Fixes: 9cea62b2cbab ("block: don't allow splitting of a REQ_NOWAIT bio")
> > Fixes: 4b83e99ee709 ("Revert "pktcdvd: remove driver."")
> > Signed-off-by: Jens Axboe <axboe@kernel.dk>
> > [amikhalitsyn: adjust context bio_split_to_limits -> blk_queue_split]
>
> The proper syntax here would be:
>
> (backported from 3e9900f3bd7ba30d60f82b162b70a1dffe4e8e24)
> [amikhalitsyn: adjust context bio_split_to_limits -> blk_queue_split]
>
> Or if you don't have to do any change (or very minimal changes):
>
> (cherry-picked from 3e9900f3bd7ba30d60f82b162b70a1dffe4e8e24)

Fixed.

Thanks,
Alex
>
> > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
> > ---
>
> -Andrea
diff mbox series

Patch

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 789093375344..1988bb05c0c7 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2400,6 +2400,8 @@  static void pkt_submit_bio(struct bio *bio)
 	struct bio *split;
 
 	blk_queue_split(&bio);
+	if (!bio)
+		return;
 
 	pkt_dbg(2, pd, "start = %6llx stop = %6llx\n",
 		(unsigned long long)bio->bi_iter.bi_sector,