Hi Herbert, On Fri, Dec 01, 2017 at 09:35:52PM +1100, Herbert Xu wrote: > On Fri, Dec 01, 2017 at 09:11:57AM +0100, Antoine Tenart wrote: > > > > I agree this should not be the case. > > > > But: > > - Other drivers are doing this check (grep "if (!req->result)" or > > "if (req->result)" to see some of them). > > - I see at least one commit fixing the exact same issue I'm facing here, > > 393897c5156a415533ff85aa381458840417b032: > > > > crypto: ccp - Check for caller result area before using it > > > > For a hash operation, the caller doesn't have to supply a result > > area on every call so don't use it / update it if it hasn't > > been supplied. > > > > I'm not entirely sure what was the code path that leads to this, I'll > > reproduce the issue and try to understand what is going on (I clearly > > recall having this crash though). > > That's different. In that case an unconditional copy is made > regardless of whether the operation is final or update. That's > why a check is required. > > If the operation is finup/final/digest then req->result must be > set and you don't need to check it. Ah, I didn't understand your point then. Of course ->result should be allocated for finup/final/digest. The function where I fix this is called regardless of the operation that was performed, so it can be an update() as well. Thanks, Antoine -- Antoine Ténart, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
