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    SubjectRe: [PATCH 2/2] crypto: skcipher: Remove VLA usage for SKCIPHER_REQUEST_ON_STACK
    On 6 September 2018 at 10:51, Herbert Xu <herbert@gondor.apana.org.au> wrote:
    > On Thu, Sep 06, 2018 at 10:11:59AM +0200, Ard Biesheuvel wrote:
    >>
    >> That way, we will almost certainly oops on a NULL pointer dereference
    >> right after, but we at least the stack corruption.
    >
    > A crash is just as bad as a BUG_ON.
    >
    > Is this even a real problem? Do we have any users of this construct
    > that is using it on async algorithms?
    >

    Perhaps not, but it is not enforced atm.

    In any case, limiting the reqsize is going to break things, so that
    needs to occur based on the sync/async nature of the algo. That also
    means we'll corrupt the stack if we ever end up using
    SKCIPHER_REQUEST_ON_STACK() with an async algo whose reqsize is
    greater than the sync reqsize limit, so I do think some additional
    sanity check is appropriate.

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