Hi Kamil, On Thu, Nov 30, 2017 at 03:10:28PM +0100, Kamil Konieczny wrote: > On 30.11.2017 13:41, Antoine Tenart wrote: > > > > No, if we do this we'll lose the ability to export the current state. > > So maybe save it into request context: > > result_sz = crypto_ahash_digestsize(ahash); > ctx = ahash_request_ctx(areq); > > if (sreq->finish) > memcpy(sreq->state, areq->result, result_sz); > else > memcpy(sreq->state, ctx->state, result_sz); Storing the digest into a driver own buffer could improve the export ability in some *very rare* cases. If so I would suggest not to deal with the kind of test you proposed, but to have your own buffer used each time. Anyway, this has nothing to do with the fix I'm proposing here, as it would change the driver's logic, and would solve a complete different (rare) issue. The proposal here is to have a simple fix (which is similar to what can be found in some other drivers), that can easily be backported to avoid NULL pointer dereferences in older versions of the kernel. Thanks, Antoine -- Antoine Ténart, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
