On Thu, Nov 27, 2025 at 05:09:38PM +0100, Roberto Sassu wrote: > On Thu, 2025-11-27 at 15:54 +0200, Jarkko Sakkinen wrote: > > From: Jarkko Sakkinen <[email protected]> > > > > tpm2_get_pcr_allocation() does not cap any upper limit for the number of > > banks. Cap the limit to eight banks so that out of bounds values coming > > from external I/O cause on only limited harm. > > > > Cc: Roberto Sassu <[email protected]> > > Sorry, I realized that you are expecting me to review. > > I have a couple of questions: > - Could you explain better how out of bounds would occur, since one > could check the number of PCR banks? > - Is dynamic allocation that bad? And if yes, why? > - Couldn't you just check that the number of available PCR banks is > below the threshold you like and keep dynamic allocation? > - Is removing tpm1_get_pcr_allocation() improving code readability?
nr_possible_banks is read from external source i.e., neither kernel nor CPU fully control its value. This causes *uncontrolled* dynamic allocation. Thus, it must be capped to some value. > > Thanks > > Roberto BR, Jarkko
