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
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