Re: [PATCH GHAK16 V5 00/10] capabilities: do not audit log BPRM_FCAPS on set*id

On 2017-10-11 20:57, Richard Guy Briggs wrote: > The audit subsystem is adding a BPRM_FCAPS record when auditing setuid > application execution (SYSCALL execve). This is not expected as it was > supposed to be limited to when the file system actually had capabilities > in an extended attribute. It lists all capabilities making the event > really ugly to parse what is happening. The PATH record correctly > records the setuid bit and owner. Suppress the BPRM_FCAPS record on > set*id. <crickets> Serge? James? Can one of you two take this via your trees since Paul has backed down citing (reasonably) that it is mostly capabilities patches rather than audit?

> See: https://github.com/linux-audit/audit-kernel/issues/16 > > The first to eighth patches just massage the logic to make it easier to > understand. Some of them could be squashed together. > > The patch that resolves this issue is the ninth. > > It would be possible to address the original issue with a change of > "!uid_eq(new->euid, root_uid) || !uid_eq(new->uid, root_uid)" > to > "!(uid_eq(new->euid, root_uid) || uid_eq(new->uid, root_uid))" > but it took me long enough to understand this logic that I don't think > I'd be doing any favours by leaving it this difficult to understand. > > The final patch attempts to address all the conditions that need logging > based on mailing list conversations, recoginizing there is probably some > duplication in the logic. > > Passes: (ltp 20170516) > ./runltp -f syscalls -s cap > ./runltp -f securebits > ./runltp -f cap_bounds > ./runltp -f filecaps > make TARGETS=capabilities kselftest (when run locally, fails over nfs) > > Since this is mostly capabilities related rather than audit, could this go > through the capabilites (Serge) or security (James) trees please? Thanks! > > v5 > rebase on linux-security/next 4.14-rc2 > added comment block header to handle_privileged_root() > moved comment in handle_privileged_root() > moved root_privileged() check back into handle_privileged_root() > > v4 > rebase on kees' 4.13 commoncap changes > minor local func renames > > v3 > refactor into several sub-functions > convert most macros to inline funcs > > v2 > use macros to clarify intent of calculations > fix original logic error > address additional audit logging conditions > > Richard Guy Briggs (10): > capabilities: factor out cap_bprm_set_creds privileged root > capabilities: intuitive names for cap gain status > capabilities: rename has_cap to has_fcap > capabilities: use root_priveleged inline to clarify logic > capabilities: use intuitive names for id changes > capabilities: move audit log decision to function > capabilities: remove a layer of conditional logic > capabilities: invert logic for clarity > capabilities: fix logic for effective root or real root > capabilities: audit log other surprising conditions > > security/commoncap.c | 193 ++++++++++++++++++++++++++++++++++----------------- > 1 file changed, 128 insertions(+), 65 deletions(-) > > -- > 1.8.3.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-security-module" in > the body of a message to majordomo(a)vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html - RGB -- Richard Guy Briggs <rgb(a)redhat.com&gt; Sr. S/W Engineer, Kernel Security, Base Operating Systems Remote, Ottawa, Red Hat Canada IRC: rgb, SunRaycer Voice: +1.647.777.2635, Internal: (81) 32635