>> Did you notice the check "IS_ERR(bp_data)" and the corresponding reaction
>> in this update suggestion?
> 
> Yes, but bp_data may still be a valid (as in "not an error") value.

Thanks for your constructive feedback.


> Your commit a1708a2eaded836b ("KVM: s390: Improve determination of sizes in
> kvm_s390_import_bp_data()") made the code more robust, as kmalloc_array() ha
>  a builtin overflow check, and will return NULL if overflow is detected.
> However, commit 0624a8eb82efd58e ("KVM: s390: Use memdup_user() rather than
> duplicating code") dropped that safety net again.

* How much are you concerned about the shown software evolution around
  multiplications for memory allocations?

* Does there really a probability remain that an inappropriate product
  would be calculated here (as the situation was before my two update steps
  for this software module)?

* Can it be that you are looking for a variant of a function like "memdup_user"
  where values can be passed as separate parameters "count" and "size" so that
  the needed multiplication and corresponding overflow check would be performed
  together as desired?

Regards,
Markus

Reply via email to