Re: [PATCH v2] selinux: hooks: use kmalloc() to allocate path buffer

[Mike Rapoport <rppt@kernel.org>]

On Sun, May 31, 2026 at 05:18:11PM +0100, David Laight wrote:
> On Sun, 31 May 2026 18:15:02 +0300
> Mike Rapoport <rppt@kernel.org> wrote:
> 
> > From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
> > 
> > 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@kernel.org>
> > ---
> > v2 changes:
> > * explicitly use kmalloc() with PATH_MAX
> > 
> >  security/selinux/hooks.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> > index 0f704380a8c8..19493198ece1 100644
> > --- a/security/selinux/hooks.c
> > +++ b/security/selinux/hooks.c
> > @@ -1336,11 +1336,11 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
> >  	struct super_block *sb = dentry->d_sb;
> >  	char *buffer, *path;
> >  
> > -	buffer = (char *)__get_free_page(GFP_KERNEL);
> > +	buffer = kmalloc(GFP_KERNEL, PATH_MAX);
> 
> At least get the args in the right order.

oops
 

-- 
Sincerely yours,
Mike.