| Message ID | 1501545093-56634-6-git-send-email-keescook@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 31 Jul 2017, Kees Cook wrote: > The SELinux bprm_secureexec hook can be merged with the bprm_set_creds > hook since it's dealing with the same information, and all of the details > are finalized during the first call to the bprm_set_creds hook via > prepare_binprm() (subsequent calls due to binfmt_script, etc, are ignored > via bprm->called_set_creds). > > Here, the test can just happen at the end of the bprm_set_creds hook, > and the bprm_secureexec hook can be dropped. > > Cc: Stephen Smalley <sds@tycho.nsa.gov> > Signed-off-by: Kees Cook <keescook@chromium.org> > Acked-by: Paul Moore <paul@paul-moore.com> > Tested-by: Paul Moore <paul@paul-moore.com> > Acked-by: Serge Hallyn <serge@hallyn.com> > --- > security/selinux/hooks.c | 24 +++++------------------- > 1 file changed, 5 insertions(+), 19 deletions(-) Reviewed-by: James Morris <james.l.morris@oracle.com>
On Mon, Jul 31, 2017 at 4:51 PM, Kees Cook <keescook@chromium.org> wrote: > The SELinux bprm_secureexec hook can be merged with the bprm_set_creds > hook since it's dealing with the same information, and all of the details > are finalized during the first call to the bprm_set_creds hook via > prepare_binprm() (subsequent calls due to binfmt_script, etc, are ignored > via bprm->called_set_creds). > > Here, the test can just happen at the end of the bprm_set_creds hook, > and the bprm_secureexec hook can be dropped. > > Cc: Stephen Smalley <sds@tycho.nsa.gov> > Signed-off-by: Kees Cook <keescook@chromium.org> > Acked-by: Paul Moore <paul@paul-moore.com> > Tested-by: Paul Moore <paul@paul-moore.com> > Acked-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Andy Lutomirski <luto@kernel.org>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 5d4051541518..edbc1c76964e 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2414,30 +2414,17 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm) /* Clear any possibly unsafe personality bits on exec: */ bprm->per_clear |= PER_CLEAR_ON_SETID; - } - - return 0; -} - -static int selinux_bprm_secureexec(struct linux_binprm *bprm) -{ - const struct task_security_struct *tsec = current_security(); - u32 sid, osid; - int atsecure = 0; - - sid = tsec->sid; - osid = tsec->osid; - if (osid != sid) { /* Enable secure mode for SIDs transitions unless the noatsecure permission is granted between the two SIDs, i.e. ahp returns 0. */ - atsecure = avc_has_perm(osid, sid, - SECCLASS_PROCESS, - PROCESS__NOATSECURE, NULL); + rc = avc_has_perm(old_tsec->sid, new_tsec->sid, + SECCLASS_PROCESS, PROCESS__NOATSECURE, + NULL); + bprm->secureexec |= !!rc; } - return !!atsecure; + return 0; } static int match_file(const void *p, struct file *file, unsigned fd) @@ -6152,7 +6139,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(bprm_set_creds, selinux_bprm_set_creds), LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds), LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds), - LSM_HOOK_INIT(bprm_secureexec, selinux_bprm_secureexec), LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security), LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),