Re: [PATCH v2 1/2] x86/fpu: Fix memory leak with dynamic fpstate and exec()

[Chang S. Bae]

On 10/14/2026 5:19 PM, Chang S. Bae wrote:
> On 10/7/2026 10:59 PM, Guixiong Wei wrote:
> > -void fpstate_free(struct fpu *fpu)
> > +void fpstate_free(struct fpstate *fpstate)
> >   {
> > -    if (fpu->fpstate && fpu->fpstate != &fpu->__fpstate)
> > -        vfree(fpu->fpstate);
> > +    if (fpstate && fpstate->is_valloc)
> > +        vfree(fpstate);
> >   }
>
> Shouldn't is_valloc be cleared here, or when fpstate_reset() replaces 
> fpu->fpstate with the embedded fpstate?

No, is_valloc is pat of the vmalloc'ed memory itself.

That said, removing the original check does not seem reassuring either. 
Maybe, another option would be adding an internal helper:

  void __fpstate_reset(struct fpstate *fpstate)
  {
      if (fpstate && fpstate->is_valloc)
          vfree(fpstate);
  }

Then, refactor fpstate_realloc() and replace the vfree() in 
fpstate_free() with it, keeping the fpstate_free() prototype unchanged.

Thanks,
Chang