On Thu, Jan 12, 2012 at 9:58 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: > On Thu, Jan 12, 2012 at 6:12 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: >> With this set, a lot of dangerous operations (chroot, unshare, etc) >> become a lot less dangerous because there is no possibility of >> subverting privileged binaries. >> >> This patch completely breaks apparmor. Someone who understands (and >> uses) apparmor should fix it or at least give me a hint. >> >> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx> >> [....] >> diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c >> index c1e18ba..7f480b7 100644 >> --- a/security/apparmor/domain.c >> +++ b/security/apparmor/domain.c >> @@ -360,6 +360,9 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) >> if (bprm->cred_prepared) >> return 0; >> >> + /* XXX: someone who understands apparmor needs to fix this. */ >> + BUG_ON(bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS); >> + >> cxt = bprm->cred->security; >> BUG_ON(!cxt); >> > > Since apparmor_bprm_set_creds() calls cap_bprm_set_creds() already[1], > I think AppArmor needs no changes at all, but John will know better. > :) I think that AppArmor determines what a program is allowed to do by looking at the path of the executable. We don't want newly-executed programs to gain permissions because they're a different executable when we're in no_new_privs mode, so (if I'm right) something different needs to happen. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
