Re: [PATCH v3] selinux: hooks: use kmalloc() to allocate path buffer

[Paul Moore]

On Tue, Jun 2, 2026 at 6:20 AM Mike Rapoport <rppt@xxxxxxxxxx> wrote:
> On Mon, Jun 01, 2026 at 02:11:11PM -0400, Paul Moore wrote:
> > On Sun, May 31, 2026 at 12:58 PM Mike Rapoport <rppt@xxxxxxxxxx> wrote:
> > >
> > > From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx>
> > >
> > > selinux_genfs_get_sid() allocates memory for a path with __get_free_page().
> > >
> > > Such usage does not require a "page" and the size of the buffer should
> > > actually be PATH_MAX which may be less than PAGE_SIZE on some
> > > architectures.
> > >
> > > Replace __get_free_page() for allocation of a path buffer with kmalloc()
> > > and make it explicit that the buffer size is PATH_MAX.
> > >
> > > Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
> > > ---
> > > v3:
> > > get the args in the right order
> > >
> > > v2:
> > > * explicitly use kmalloc() with PATH_MAX
> > >
> > >  security/selinux/hooks.c | 6 +++---
> > >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > Considering the problems with the first two versions of this patch I
> > have to ask what sort of testing you've done on this?  I know it's a
> > trivial patch, but we're on v3 ...
>
> Boot of fedora on an arm64 VM with 64K page size kernel.

Given the minimal testing, the problems with the previous versions,
and the fact that we are at -rc6, I'm going to hold this for the next
dev cycle.

-- 
paul-moore.com