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[PATCH v2] md: raid1: fix potential OOB in raid1_remove_disk()

Zhang Shurong posted 1 patch 2 years, 6 months ago 
drivers/md/raid1.c | 4 ++++
1 file changed, 4 insertions(+)
[PATCH v2] md: raid1: fix potential OOB in raid1_remove_disk()
Posted by Zhang Shurong 2 years, 6 months ago 
If rddev->raid_disk is greater than mddev->raid_disks, there will be
an out-of-bounds in raid1_remove_disk(). We have already found
similar reports as follows:

1) commit d17f744e883b ("md-raid10: fix KASAN warning")
2) commit 1ebc2cec0b7d ("dm raid: fix KASAN warning in raid5_remove_disk")

Fix this bug by checking whether the "number" variable is
valid.

Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
---
Changes in v2:
 - Using conf->raid_disks instead of mddev->raid_disks.

 drivers/md/raid1.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index dd25832eb045..80aeee63dfb7 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1829,6 +1829,10 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
 	struct r1conf *conf = mddev->private;
 	int err = 0;
 	int number = rdev->raid_disk;
+
+	if (unlikely(number >= conf->raid_disks))
+		goto abort;
+
 	struct raid1_info *p = conf->mirrors + number;
 
 	if (rdev != p->rdev)
-- 
2.41.0
Re: [PATCH v2] md: raid1: fix potential OOB in raid1_remove_disk()
Posted by Yu Kuai 2 years, 6 months ago 
在 2023/07/22 15:53, Zhang Shurong 写道:
> If rddev->raid_disk is greater than mddev->raid_disks, there will be
> an out-of-bounds in raid1_remove_disk(). We have already found
> similar reports as follows:
> 
> 1) commit d17f744e883b ("md-raid10: fix KASAN warning")
> 2) commit 1ebc2cec0b7d ("dm raid: fix KASAN warning in raid5_remove_disk")
> 
> Fix this bug by checking whether the "number" variable is
> valid.

LGTM

Reviewed-by: Yu Kuai <yukuai3@huawei.com>
> 
> Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
> ---
> Changes in v2:
>   - Using conf->raid_disks instead of mddev->raid_disks.
> 
>   drivers/md/raid1.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
> index dd25832eb045..80aeee63dfb7 100644
> --- a/drivers/md/raid1.c
> +++ b/drivers/md/raid1.c
> @@ -1829,6 +1829,10 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
>   	struct r1conf *conf = mddev->private;
>   	int err = 0;
>   	int number = rdev->raid_disk;
> +
> +	if (unlikely(number >= conf->raid_disks))
> +		goto abort;
> +
>   	struct raid1_info *p = conf->mirrors + number;
>   
>   	if (rdev != p->rdev)
>
Re: [PATCH v2] md: raid1: fix potential OOB in raid1_remove_disk()
Posted by Song Liu 2 years, 6 months ago 
On Mon, Jul 24, 2023 at 10:12 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>
> 在 2023/07/22 15:53, Zhang Shurong 写道:
> > If rddev->raid_disk is greater than mddev->raid_disks, there will be
> > an out-of-bounds in raid1_remove_disk(). We have already found
> > similar reports as follows:
> >
> > 1) commit d17f744e883b ("md-raid10: fix KASAN warning")
> > 2) commit 1ebc2cec0b7d ("dm raid: fix KASAN warning in raid5_remove_disk")
> >
> > Fix this bug by checking whether the "number" variable is
> > valid.
>
> LGTM
>
> Reviewed-by: Yu Kuai <yukuai3@huawei.com>
> >
> > Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
> > ---
> > Changes in v2:
> >   - Using conf->raid_disks instead of mddev->raid_disks.
> >
> >   drivers/md/raid1.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
> > index dd25832eb045..80aeee63dfb7 100644
> > --- a/drivers/md/raid1.c
> > +++ b/drivers/md/raid1.c
> > @@ -1829,6 +1829,10 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
> >       struct r1conf *conf = mddev->private;
> >       int err = 0;
> >       int number = rdev->raid_disk;
> > +
> > +     if (unlikely(number >= conf->raid_disks))
> > +             goto abort;

We need err = -EINVAL here.

> > +
> >       struct raid1_info *p = conf->mirrors + number;
> >
> >       if (rdev != p->rdev)
> >
>
Re: [PATCH v2] md: raid1: fix potential OOB in raid1_remove_disk()
Posted by Yu Kuai 2 years, 6 months ago 
Hi,

在 2023/07/29 18:49, Song Liu 写道:
> On Mon, Jul 24, 2023 at 10:12 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>>
>> 在 2023/07/22 15:53, Zhang Shurong 写道:
>>> If rddev->raid_disk is greater than mddev->raid_disks, there will be
>>> an out-of-bounds in raid1_remove_disk(). We have already found
>>> similar reports as follows:
>>>
>>> 1) commit d17f744e883b ("md-raid10: fix KASAN warning")
>>> 2) commit 1ebc2cec0b7d ("dm raid: fix KASAN warning in raid5_remove_disk")
>>>
>>> Fix this bug by checking whether the "number" variable is
>>> valid.
>>
>> LGTM
>>
>> Reviewed-by: Yu Kuai <yukuai3@huawei.com>
>>>
>>> Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
>>> ---
>>> Changes in v2:
>>>    - Using conf->raid_disks instead of mddev->raid_disks.
>>>
>>>    drivers/md/raid1.c | 4 ++++
>>>    1 file changed, 4 insertions(+)
>>>
>>> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
>>> index dd25832eb045..80aeee63dfb7 100644
>>> --- a/drivers/md/raid1.c
>>> +++ b/drivers/md/raid1.c
>>> @@ -1829,6 +1829,10 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
>>>        struct r1conf *conf = mddev->private;
>>>        int err = 0;
>>>        int number = rdev->raid_disk;
>>> +
>>> +     if (unlikely(number >= conf->raid_disks))
>>> +             goto abort;
> 
> We need err = -EINVAL here.

I think return 0 is right here, so that caller can remove this rdev
from array successfully, this only need to return error for the case
-EBUSY.

Thanks,
Kuai

> 
>>> +
>>>        struct raid1_info *p = conf->mirrors + number;
>>>
>>>        if (rdev != p->rdev)
>>>
>>
> .
>
Re: [PATCH v2] md: raid1: fix potential OOB in raid1_remove_disk()
Posted by Song Liu 2 years, 5 months ago 
On Mon, Jul 31, 2023 at 5:08 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>
> Hi,
>
> 在 2023/07/29 18:49, Song Liu 写道:
> > On Mon, Jul 24, 2023 at 10:12 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
> >>
> >> 在 2023/07/22 15:53, Zhang Shurong 写道:
> >>> If rddev->raid_disk is greater than mddev->raid_disks, there will be
> >>> an out-of-bounds in raid1_remove_disk(). We have already found
> >>> similar reports as follows:
> >>>
> >>> 1) commit d17f744e883b ("md-raid10: fix KASAN warning")
> >>> 2) commit 1ebc2cec0b7d ("dm raid: fix KASAN warning in raid5_remove_disk")
> >>>
> >>> Fix this bug by checking whether the "number" variable is
> >>> valid.
> >>
> >> LGTM
> >>
> >> Reviewed-by: Yu Kuai <yukuai3@huawei.com>
> >>>
> >>> Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
> >>> ---
> >>> Changes in v2:
> >>>    - Using conf->raid_disks instead of mddev->raid_disks.
> >>>
> >>>    drivers/md/raid1.c | 4 ++++
> >>>    1 file changed, 4 insertions(+)
> >>>
> >>> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
> >>> index dd25832eb045..80aeee63dfb7 100644
> >>> --- a/drivers/md/raid1.c
> >>> +++ b/drivers/md/raid1.c
> >>> @@ -1829,6 +1829,10 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
> >>>        struct r1conf *conf = mddev->private;
> >>>        int err = 0;
> >>>        int number = rdev->raid_disk;
> >>> +
> >>> +     if (unlikely(number >= conf->raid_disks))
> >>> +             goto abort;
> >
> > We need err = -EINVAL here.
>
> I think return 0 is right here, so that caller can remove this rdev
> from array successfully, this only need to return error for the case
> -EBUSY.

Ah, that's right. Applied to md-next.

Thanks,
Song

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