On Mon, Sep 25, 2017 at 11:37 PM, Steve Grubb <sgrubb(a)redhat.com> wrote:
On Monday, September 25, 2017 2:49:19 PM EDT Amir Goldstein wrote:
...
> >
> > + if (flags & FAN_ENABLE_AUDIT) {
> > + fd = -EPERM;
> > + if (!capable(CAP_AUDIT_WRITE))
> > + goto out_destroy_group;
> > + group->audit_enabled = 1;
> > + }
> > +
>
> App should not be able to enable audit if audit is not configured in kernel.
> So there should be code that returns EINVAL for flag FAN_ENABLE_AUDIT if
> CONFIG_AUDITSYSCALL is not defined.
> Same deal as flag FAN_ALL_PERM_EVENTS and kernel config
> CONFIG_FANOTIFY_ACCESS_PERMISSIONS in fanotify_mark().
> Perhaps it is better not to extend FAN_ALL_INIT_FLAGS and explicitly
> test (flags & ~(FAN_ALL_INIT_FLAGS | FAN_ENABLE_AUDIT)) in fanotify_init()
> under ifdef, as done in fanotify_mark()?
OK. How about this, I do the (flags & ~(FAN_ALL_INIT_FLAGS |
FAN_ENABLE_AUDIT)) with an ifdef. This will cause -EINVAL if FAN_ENABLE_AUDIT
is attempted and CONFIG_AUDITSYSCALL is not defined. So, the code initially
discussed above for audit_enabled would not need to have an #else. I can
surround the "if" block with a CONFIG_AUDITSYSCALL so that it compiles out if
audit is not being used. This will cause audit_enabled to always be false when
audit is not compiled in.
Sure. only there is no need for wrapping the if block with ifdef as the flag
FAN_ENABLE_AUDIT is already not possible due to the first check, so by
rule of "use bare minimum ifdefs" there is no need for the second ifdef.
Amir.