Re: [PATCH] arm64: Avoid premature usercopy failure

From: Will Deacon
Date: Thu Jul 15 2021 - 13:39:16 EST


On Mon, 12 Jul 2021 15:27:46 +0100, Robin Murphy wrote:
> Al reminds us that the usercopy API must only return complete failure
> if absolutely nothing could be copied. Currently, if userspace does
> something silly like giving us an unaligned pointer to Device memory,
> or a size which overruns MTE tag bounds, we may fail to honour that
> requirement when faulting on a multi-byte access even though a smaller
> access could have succeeded.
>
> [...]

Applied to arm64 (for-next/fixes), thanks!

[1/1] arm64: Avoid premature usercopy failure
https://git.kernel.org/arm64/c/295cf156231c

Cheers,
--
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev