On Thu, Feb 20, 2025 at 11:43 AM Stephen Smalley
<stephen.smalley.work@xxxxxxxxx> wrote:
> On Wed, Oct 23, 2024 at 5:23 PM Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
> >
> > Replace the (secctx,seclen) pointer pair with a single lsm_context
> > pointer to allow return of the LSM identifier along with the context
> > and context length. This allows security_release_secctx() to know how
> > to release the context. Callers have been modified to use or save the
> > returned data from the new structure.
> >
> > Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
> > Cc: ceph-devel@xxxxxxxxxxxxxxx
> > Cc: linux-nfs@xxxxxxxxxxxxxxx
> > ---
> > fs/ceph/super.h | 3 +--
> > fs/ceph/xattr.c | 16 ++++++----------
> > fs/fuse/dir.c | 35 ++++++++++++++++++-----------------
> > fs/nfs/nfs4proc.c | 20 ++++++++++++--------
> > include/linux/lsm_hook_defs.h | 2 +-
> > include/linux/security.h | 26 +++-----------------------
> > security/security.c | 9 ++++-----
> > security/selinux/hooks.c | 9 +++++----
> > 8 files changed, 50 insertions(+), 70 deletions(-)
> >
>
> > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> > index 76776d716744..0b116ef3a752 100644
> > --- a/fs/nfs/nfs4proc.c
> > +++ b/fs/nfs/nfs4proc.c
> > @@ -114,6 +114,7 @@ static inline struct nfs4_label *
> > nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
> > struct iattr *sattr, struct nfs4_label *label)
> > {
> > + struct lsm_context shim;
> > int err;
> >
> > if (label == NULL)
> > @@ -128,21 +129,24 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
> > label->label = NULL;
> >
> > err = security_dentry_init_security(dentry, sattr->ia_mode,
> > - &dentry->d_name, NULL,
> > - (void **)&label->label, &label->len);
> > - if (err == 0)
> > - return label;
> > + &dentry->d_name, NULL, &shim);
> > + if (err)
> > + return NULL;
> >
> > - return NULL;
> > + label->label = shim.context;
> > + label->len = shim.len;
> > + return label;
> > }
> > static inline void
> > nfs4_label_release_security(struct nfs4_label *label)
> > {
> > - struct lsm_context scaff; /* scaffolding */
> > + struct lsm_context shim;
> >
> > if (label) {
> > - lsmcontext_init(&scaff, label->label, label->len, 0);
> > - security_release_secctx(&scaff);
> > + shim.context = label->label;
> > + shim.len = label->len;
> > + shim.id = LSM_ID_UNDEF;
>
> Is there a patch that follows this one to fix this? Otherwise, setting
> this to UNDEF causes SELinux to NOT free the context, which produces a
> memory leak for every NFS inode security context. Reported by kmemleak
> when running the selinux-testsuite NFS tests.
I don't recall seeing anything related to this, but patches are
definitely welcome.
--
paul-moore.com
