This is a note to let you know that I've just added the patch titled
md: don't rely on 'mddev->pers' to be set in mddev_suspend()
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
md-don-t-rely-on-mddev-pers-to-be-set-in-mddev_suspe.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ff995c501649ac2ea35de819751069e44a8b880e
Author: Yu Kuai <yukuai3@xxxxxxxxxx>
Date: Fri Aug 25 11:09:52 2023 +0800
md: don't rely on 'mddev->pers' to be set in mddev_suspend()
[ Upstream commit b721e7885eb242aa2459ee66bb42ceef1bcf0f0c ]
'active_io' used to be initialized while the array is running, and
'mddev->pers' is set while the array is running as well. Hence caller
must hold 'reconfig_mutex' and guarantee 'mddev->pers' is set before
calling mddev_suspend().
Now that 'active_io' is initialized when mddev is allocated, such
restriction doesn't exist anymore. In the meantime, follow up patches
will refactor mddev_suspend(), hence add checking for 'mddev->pers' to
prevent null-ptr-deref.
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Signed-off-by: Song Liu <song@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230825030956.1527023-4-yukuai1@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index a104a025084dc..9247e55c7eafc 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -449,7 +449,7 @@ void mddev_suspend(struct mddev *mddev)
set_bit(MD_ALLOW_SB_UPDATE, &mddev->flags);
percpu_ref_kill(&mddev->active_io);
- if (mddev->pers->prepare_suspend)
+ if (mddev->pers && mddev->pers->prepare_suspend)
mddev->pers->prepare_suspend(mddev);
wait_event(mddev->sb_wait, percpu_ref_is_zero(&mddev->active_io));
