[PATCH] ubi: fastmap: fix slab corruption

[Richard Weinberger]

Rabin,

Am 20.03.2017 um 16:17 schrieb Rabin Vincent:
> From: Rabin Vincent <rabinv at axis.com>
> 
> Booting with UBI fastmap and SLUB debugging enabled results in the
> following splats.  The problem is that ubi_scan_fastmap() moves the
> fastmap blocks from the scan_ai (allocated in scan_fast()) to the ai
> allocated in ubi_attach().  This results in two problems:
> 
>  - When the scan_ai is freed, aebs which were allocated from its slab
>    cache are still in use.
> 
>  - When the other ai is being destroyed in destroy_ai(), the
>    arguments to kmem_cache_free() call are incorrect since aebs on its
>    ->fastmap list were allocated with a slab cache from a differnt ai.
> 
> Fix this by making a copy of the aebs in ubi_scan_fastmap() instead of
> moving them.

Is this new in 4.9? I'm a bit confused because I fixed such SLUB related
issues some time ago already in Fastmap.

Thanks,
//richard