• Stephan Mueller's avatar
    crypto: drbg - prevent invalid SG mappings · 51029812
    Stephan Mueller authored
    When using SGs, only heap memory (memory that is valid as per
    virt_addr_valid) is allowed to be referenced. The CTR DRBG used to
    reference the caller-provided memory directly in an SG. In case the
    caller provided stack memory pointers, the SG mapping is not considered
    to be valid. In some cases, this would even cause a paging fault.
    The change adds a new scratch buffer that is used unconditionally to
    catch the cases where the caller-provided buffer is not suitable for
    use in an SG. The crypto operation of the CTR DRBG produces its output
    with that scratch buffer and finally copies the content of the
    scratch buffer to the caller's buffer.
    The scratch buffer is allocated during allocation time of the CTR DRBG
    as its access is protected with the DRBG mutex.
    Signed-off-by: default avatarStephan Mueller <smueller@chronox.de>
    Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
drbg.h 9.01 KB