| Message ID | 36700dd2a846de06fc5f6585e94d2f261f6f3083.1504591358.git.rgb@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Sep 4, 2017 at 11:46 PM, Richard Guy Briggs <rgb@redhat.com> wrote: > Move the audit log decision logic to its own function to isolate the > complexity in one place. > > Suggested-by: Serge Hallyn <serge@hallyn.com> > Signed-off-by: Richard Guy Briggs <rgb@redhat.com> > Reviewed-by: Serge Hallyn <serge@hallyn.com> > Acked-by: James Morris <james.l.morris@oracle.com> Acked-by: Kees Cook <keescook@chromium.org> -Kees > --- > security/commoncap.c | 50 ++++++++++++++++++++++++++++++-------------------- > 1 files changed, 30 insertions(+), 20 deletions(-) > > diff --git a/security/commoncap.c b/security/commoncap.c > index d37ebec..eae7431 100644 > --- a/security/commoncap.c > +++ b/security/commoncap.c > @@ -527,6 +527,32 @@ static inline bool __is_setuid(struct cred *new, const struct cred *old) > static inline bool __is_setgid(struct cred *new, const struct cred *old) > { return !gid_eq(new->egid, old->gid); } > > +/* > + * Audit candidate if current->cap_effective is set > + * > + * We do not bother to audit if 3 things are true: > + * 1) cap_effective has all caps > + * 2) we are root > + * 3) root is supposed to have all caps (SECURE_NOROOT) > + * Since this is just a normal root execing a process. > + * > + * Number 1 above might fail if you don't have a full bset, but I think > + * that is interesting information to audit. > + */ > +static inline bool nonroot_raised_pE(struct cred *cred, kuid_t root) > +{ > + bool ret = false; > + > + if (__cap_grew(effective, ambient, cred)) { > + if (!__cap_full(effective, cred) || > + !__is_eff(root, cred) || !__is_real(root, cred) || > + !root_privileged()) { > + ret = true; > + } > + } > + return ret; > +} > + > /** > * cap_bprm_set_creds - Set up the proposed credentials for execve(). > * @bprm: The execution parameters, including the proposed creds > @@ -604,26 +630,10 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) > if (WARN_ON(!cap_ambient_invariant_ok(new))) > return -EPERM; > > - /* > - * Audit candidate if current->cap_effective is set > - * > - * We do not bother to audit if 3 things are true: > - * 1) cap_effective has all caps > - * 2) we are root > - * 3) root is supposed to have all caps (SECURE_NOROOT) > - * Since this is just a normal root execing a process. > - * > - * Number 1 above might fail if you don't have a full bset, but I think > - * that is interesting information to audit. > - */ > - if (__cap_grew(effective, ambient, new)) { > - if (!__cap_full(effective, new) || > - !__is_eff(root_uid, new) || !__is_real(root_uid, new) || > - !root_privileged()) { > - ret = audit_log_bprm_fcaps(bprm, new, old); > - if (ret < 0) > - return ret; > - } > + if (nonroot_raised_pE(new, root_uid)) { > + ret = audit_log_bprm_fcaps(bprm, new, old); > + if (ret < 0) > + return ret; > } > > new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); > -- > 1.7.1 >
diff --git a/security/commoncap.c b/security/commoncap.c index d37ebec..eae7431 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -527,6 +527,32 @@ static inline bool __is_setuid(struct cred *new, const struct cred *old) static inline bool __is_setgid(struct cred *new, const struct cred *old) { return !gid_eq(new->egid, old->gid); } +/* + * Audit candidate if current->cap_effective is set + * + * We do not bother to audit if 3 things are true: + * 1) cap_effective has all caps + * 2) we are root + * 3) root is supposed to have all caps (SECURE_NOROOT) + * Since this is just a normal root execing a process. + * + * Number 1 above might fail if you don't have a full bset, but I think + * that is interesting information to audit. + */ +static inline bool nonroot_raised_pE(struct cred *cred, kuid_t root) +{ + bool ret = false; + + if (__cap_grew(effective, ambient, cred)) { + if (!__cap_full(effective, cred) || + !__is_eff(root, cred) || !__is_real(root, cred) || + !root_privileged()) { + ret = true; + } + } + return ret; +} + /** * cap_bprm_set_creds - Set up the proposed credentials for execve(). * @bprm: The execution parameters, including the proposed creds @@ -604,26 +630,10 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) if (WARN_ON(!cap_ambient_invariant_ok(new))) return -EPERM; - /* - * Audit candidate if current->cap_effective is set - * - * We do not bother to audit if 3 things are true: - * 1) cap_effective has all caps - * 2) we are root - * 3) root is supposed to have all caps (SECURE_NOROOT) - * Since this is just a normal root execing a process. - * - * Number 1 above might fail if you don't have a full bset, but I think - * that is interesting information to audit. - */ - if (__cap_grew(effective, ambient, new)) { - if (!__cap_full(effective, new) || - !__is_eff(root_uid, new) || !__is_real(root_uid, new) || - !root_privileged()) { - ret = audit_log_bprm_fcaps(bprm, new, old); - if (ret < 0) - return ret; - } + if (nonroot_raised_pE(new, root_uid)) { + ret = audit_log_bprm_fcaps(bprm, new, old); + if (ret < 0) + return ret; } new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);