Re: [PATCH V1] audit: log xattr args not covered by syscall record

On 5/10/2021 6:28 PM, Paul Moore wrote: > On Mon, May 10, 2021 at 8:37 PM Casey Schaufler <casey(a)schaufler-ca.com&gt; wrote: >> On 5/10/2021 4:52 PM, Paul Moore wrote: >>> On Mon, May 10, 2021 at 12:30 PM Casey Schaufler <casey(a)schaufler-ca.com&gt; wrote: >>>> On 5/7/2021 6:54 PM, Richard Guy Briggs wrote: >>>>> On 2021-05-07 14:03, Casey Schaufler wrote: >>>>>> On 5/7/2021 12:55 PM, Richard Guy Briggs wrote: >>>>>>> The *setxattr syscalls take 5 arguments. The SYSCALL record only lists >>>>>>> four arguments and only lists pointers of string values. The xattr name >>>>>>> string, value string and flags (5th arg) are needed by audit given the >>>>>>> syscall's main purpose. >>>>>>> >>>>>>> Add the auxiliary record AUDIT_XATTR (1336) to record the details not >>>>>>> available in the SYSCALL record including the name string, value string >>>>>>> and flags. >>>>>>> >>>>>>> Notes about field names: >>>>>>> - name is too generic, use xattr precedent from ima >>>>>>> - val is already generic value field name >>>>>>> - flags used by mmap, xflags new name >>>>>>> >>>>>>> Sample event with new record: >>>>>>> type=PROCTITLE msg=audit(05/07/2021 12:58:42.176:189) : proctitle=filecap /tmp/ls dac_override >>>>>>> type=PATH msg=audit(05/07/2021 12:58:42.176:189) : item=0 name=(null) inode=25 dev=00:1e mode=file,755 ouid=root ogid=root rdev=00:00 obj=unconfined_u:object_r:user_tmp_t:s0 nametype=NORMAL cap_fp=none cap_fi=none cap_fe=0 cap_fver=0 cap_frootid=0 >>>>>>> type=CWD msg=audit(05/07/2021 12:58:42.176:189) : cwd=/root >>>>>>> type=XATTR msg=audit(05/07/2021 12:58:42.176:189) : xattr="security.capability" val=01 xflags=0x0 >>>>>> Would it be sensible to break out the namespace from the attribute? >>>>>> >>>>>> attrspace="security" attrname="capability" >>>>> Do xattrs always follow this nomenclature? Or only the ones we care >>>>> about? >>>> Xattrs always have a namespace (man 7 xattr) of "user", "trusted", >>>> "system" or "security". It's possible that additional namespaces will >>>> be created in the future, although it seems unlikely given that only >>>> "security" is widely used today. >>> Why should audit care about separating the name into two distinct >>> fields, e.g. "attrspace" and "attrname", instead of just a single >>> "xattr" field with a value that follows the "namespace.attribute" >>> format that is commonly seen by userspace? >> I asked if it would be sensible. I don't much care myself. > I was *asking* a question - why would we want separate fields? I > guess I thought there might be some reason for asking if it was > sensible; if not, I think I'd rather see it as a single field. I thought that it might make searching records easier, but I'm not the expert on that. One might filter on attrspace=security then look at the attrname values. But that bikeshed can be either color.