Re: [PATCH] sparc: copy_from_user() should not return -EFAULT

[Andi Kleen]

Heiko Carstens <heiko.carstens@xxxxxxxxxx> writes:

> Subject: [PATCH] sparc: copy_from_user() should not return -EFAULT
>
> From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
>
> Callers of copy_from_user() expect it to return the number of bytes
> it could not copy. In no case it is supposed to return -EFAULT.
>
> In case of a detected buffer overflow just return the requested
> length. In addition one could think of a memset that would clear
> the size of the target object.

Ouch! I would expect this is likely exploitable, e.g. in mount

-Andi

-- 
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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