| Message ID | 20241023212158.18718-6-casey@schaufler-ca.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Delegated to: | Paul Moore |
| Headers | show |
| Series | [v3,1/5] LSM: Ensure the correct LSM context releaser | expand |
On Oct 23, 2024 Casey Schaufler <casey@schaufler-ca.com> wrote: > > Verify that the LSM releasing the secctx is the LSM that > allocated it. This was not necessary when only one LSM could > create a secctx, but once there can be more than one it is. > > Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> > --- > security/apparmor/secid.c | 13 +++++-------- > security/selinux/hooks.c | 13 +++++-------- > 2 files changed, 10 insertions(+), 16 deletions(-) See my note on patch 1/5, merging into lsm/dev. -- paul-moore.com
diff --git a/security/apparmor/secid.c b/security/apparmor/secid.c index 5d92fc3ab8b4..854613e58e34 100644 --- a/security/apparmor/secid.c +++ b/security/apparmor/secid.c @@ -122,14 +122,11 @@ int apparmor_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) void apparmor_release_secctx(struct lsm_context *cp) { - /* - * stacking scaffolding: - * When it is possible for more than one LSM to provide a - * release hook, do this check: - * if (cp->id == LSM_ID_APPARMOR || cp->id == LSM_ID_UNDEF) - */ - - kfree(cp->context); + if (cp->id == LSM_ID_APPARMOR) { + kfree(cp->context); + cp->context = NULL; + cp->id = LSM_ID_UNDEF; + } } /** diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 79776a5e651d..996e765b6823 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -6640,14 +6640,11 @@ static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) static void selinux_release_secctx(struct lsm_context *cp) { - /* - * stacking scaffolding: - * When it is possible for more than one LSM to provide a - * release hook, do this check: - * if (cp->id == LSM_ID_SELINUX || cp->id == LSM_ID_UNDEF) - */ - - kfree(cp->context); + if (cp->id == LSM_ID_SELINUX) { + kfree(cp->context); + cp->context = NULL; + cp->id = LSM_ID_UNDEF; + } } static void selinux_inode_invalidate_secctx(struct inode *inode)
Verify that the LSM releasing the secctx is the LSM that allocated it. This was not necessary when only one LSM could create a secctx, but once there can be more than one it is. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> --- security/apparmor/secid.c | 13 +++++-------- security/selinux/hooks.c | 13 +++++-------- 2 files changed, 10 insertions(+), 16 deletions(-)