• Herbert Xu's avatar
    crypto: padlock-aes - Fix Nano workaround data corruption · 46d8c4b2
    Herbert Xu authored
    This was detected by the self-test thanks to Ard's chunking patch.
    
    I finally got around to testing this out on my ancient Via box.  It
    turns out that the workaround got the assembly wrong and we end up
    doing count + initial cycles of the loop instead of just count.
    
    This obviously causes corruption, either by overwriting the source
    that is yet to be processed, or writing over the end of the buffer.
    
    On CPUs that don't require the workaround only ECB is affected.
    On Nano CPUs both ECB and CBC are affected.
    
    This patch fixes it by doing the subtraction prior to the assembly.
    
    Fixes: a76c1c23 ("crypto: padlock-aes - work around Nano CPU...")
    Cc: <stable@vger.kernel.org>
    Reported-by: default avatarJamie Heilman <jamie@audible.transient.net>
    Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
    46d8c4b2
padlock-aes.c 14.6 KB