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.
> + security_release_secctx(&shim);
> }
> }
> static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label)
