Re: [PATCH 5.15 089/779] md-raid10: fix KASAN warning

[Pavel Machek]

Hi!

> From: Mikulas Patocka <mpatocka@xxxxxxxxxx>
> 
> commit d17f744e883b2f8d13cca252d71cfe8ace346f7d upstream.
> 
> There's a KASAN warning in raid10_remove_disk when running the lvm
> test lvconvert-raid-reshape.sh. We fix this warning by verifying that the
> value "number" is valid.
> 
> BUG: KASAN: slab-out-of-bounds in raid10_remove_disk+0x61/0x2a0 [raid10]
> Read of size 8 at addr ffff889108f3d300 by task mdX_raid10/124682

Is this place for array_index_nospec?

Best regards,
								Pavel

> --- a/drivers/md/raid10.c
> +++ b/drivers/md/raid10.c
> @@ -2139,9 +2139,12 @@ static int raid10_remove_disk(struct mdd
>  	int err = 0;
>  	int number = rdev->raid_disk;
>  	struct md_rdev **rdevp;
> -	struct raid10_info *p = conf->mirrors + number;
> +	struct raid10_info *p;
>  
>  	print_conf(conf);
> +	if (unlikely(number >= mddev->raid_disks))
> +		return 0;
> +	p = conf->mirrors + number;
>  	if (rdev == p->rdev)
>  		rdevp = &p->rdev;
>  	else if (rdev == p->replacement)
> 

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DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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