[PATCH v3 0/6] Memory corruption may occur due to incorrent tlb flush

[Greg KH]

On Thu, Mar 12, 2020 at 06:57:34PM +0530, Santosh Sivaraj wrote:
> The TLB flush optimisation (a46cc7a90f: powerpc/mm/radix: Improve TLB/PWC
> flushes) may result in random memory corruption. Any concurrent page-table walk
> could end up with a Use-after-Free. Even on UP this might give issues, since
> mmu_gather is preemptible these days. An interrupt or preempted task accessing
> user pages might stumble into the free page if the hardware caches page
> directories.
> 
> The series is a backport of the fix sent by Peter [1].
> 
> The first three patches are dependencies for the last patch (avoid potential
> double flush). If the performance impact due to double flush is considered
> trivial then the first three patches and last patch may be dropped.
> 
> This is only for v4.19 stable.
> 
> [1] https://patchwork.kernel.org/cover/11284843/

Sorry for the delay, now queued up, let's see what the test-builders say
about it...

thanks,

greg k-h