Re: [PATCH v3] audit: log nftables configuration change events once per table

From: Richard Guy Briggs
Date: Wed Mar 24 2021 - 23:16:53 EST


On 2021-03-24 12:32, Paul Moore wrote:
> On Tue, Mar 23, 2021 at 4:05 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> >
> > Reduce logging of nftables events to a level similar to iptables.
> > Restore the table field to list the table, adding the generation.
> >
> > Indicate the op as the most significant operation in the event.
> >
> > A couple of sample events:
> >
> > type=PROCTITLE msg=audit(2021-03-18 09:30:49.801:143) : proctitle=/usr/bin/python3 -s /usr/sbin/firewalld --nofork --nopid
> > type=SYSCALL msg=audit(2021-03-18 09:30:49.801:143) : arch=x86_64 syscall=sendmsg success=yes exit=172 a0=0x6 a1=0x7ffdcfcbe650 a2=0x0 a3=0x7ffdcfcbd52c items=0 ppid=1 pid=367 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=roo
> > t sgid=root fsgid=root tty=(none) ses=unset comm=firewalld exe=/usr/bin/python3.9 subj=system_u:system_r:firewalld_t:s0 key=(null)
> > type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.801:143) : table=firewalld:2 family=ipv6 entries=1 op=nft_register_table pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
> > type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.801:143) : table=firewalld:2 family=ipv4 entries=1 op=nft_register_table pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
> > type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.801:143) : table=firewalld:2 family=inet entries=1 op=nft_register_table pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
> >
> > type=PROCTITLE msg=audit(2021-03-18 09:30:49.839:144) : proctitle=/usr/bin/python3 -s /usr/sbin/firewalld --nofork --nopid
> > type=SYSCALL msg=audit(2021-03-18 09:30:49.839:144) : arch=x86_64 syscall=sendmsg success=yes exit=22792 a0=0x6 a1=0x7ffdcfcbe650 a2=0x0 a3=0x7ffdcfcbd52c items=0 ppid=1 pid=367 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=r
> > oot sgid=root fsgid=root tty=(none) ses=unset comm=firewalld exe=/usr/bin/python3.9 subj=system_u:system_r:firewalld_t:s0 key=(null)
> > type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.839:144) : table=firewalld:3 family=ipv6 entries=30 op=nft_register_chain pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
> > type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.839:144) : table=firewalld:3 family=ipv4 entries=30 op=nft_register_chain pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
> > type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.839:144) : table=firewalld:3 family=inet entries=165 op=nft_register_chain pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
> >
> > The issue was originally documented in
> > https://github.com/linux-audit/audit-kernel/issues/124
> >
> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> > ---
> > Changelog:
> > v3:
> > - fix function braces, reduce parameter scope
> > - pre-allocate nft_audit_data per table in step 1, bail on ENOMEM
> >
> > v2:
> > - convert NFT ops to array indicies in nft2audit_op[]
> > - use linux lists
> > - use functions for each of collection and logging of audit data
> > ---
> > include/linux/audit.h | 28 ++++++
> > net/netfilter/nf_tables_api.c | 160 ++++++++++++++++------------------
> > 2 files changed, 105 insertions(+), 83 deletions(-)
>
> ...
>
> > diff --git a/include/linux/audit.h b/include/linux/audit.h
> > index 82b7c1116a85..5fafcf4c13de 100644
> > --- a/include/linux/audit.h
> > +++ b/include/linux/audit.h
> > @@ -118,6 +118,34 @@ enum audit_nfcfgop {
> > AUDIT_NFT_OP_INVALID,
> > };
> >
> > +static const u8 nft2audit_op[NFT_MSG_MAX] = { // enum nf_tables_msg_types
> > + [NFT_MSG_NEWTABLE] = AUDIT_NFT_OP_TABLE_REGISTER,
> > + [NFT_MSG_GETTABLE] = AUDIT_NFT_OP_INVALID,
> > + [NFT_MSG_DELTABLE] = AUDIT_NFT_OP_TABLE_UNREGISTER,
> > + [NFT_MSG_NEWCHAIN] = AUDIT_NFT_OP_CHAIN_REGISTER,
> > + [NFT_MSG_GETCHAIN] = AUDIT_NFT_OP_INVALID,
> > + [NFT_MSG_DELCHAIN] = AUDIT_NFT_OP_CHAIN_UNREGISTER,
> > + [NFT_MSG_NEWRULE] = AUDIT_NFT_OP_RULE_REGISTER,
> > + [NFT_MSG_GETRULE] = AUDIT_NFT_OP_INVALID,
> > + [NFT_MSG_DELRULE] = AUDIT_NFT_OP_RULE_UNREGISTER,
> > + [NFT_MSG_NEWSET] = AUDIT_NFT_OP_SET_REGISTER,
> > + [NFT_MSG_GETSET] = AUDIT_NFT_OP_INVALID,
> > + [NFT_MSG_DELSET] = AUDIT_NFT_OP_SET_UNREGISTER,
> > + [NFT_MSG_NEWSETELEM] = AUDIT_NFT_OP_SETELEM_REGISTER,
> > + [NFT_MSG_GETSETELEM] = AUDIT_NFT_OP_INVALID,
> > + [NFT_MSG_DELSETELEM] = AUDIT_NFT_OP_SETELEM_UNREGISTER,
> > + [NFT_MSG_NEWGEN] = AUDIT_NFT_OP_GEN_REGISTER,
> > + [NFT_MSG_GETGEN] = AUDIT_NFT_OP_INVALID,
> > + [NFT_MSG_TRACE] = AUDIT_NFT_OP_INVALID,
> > + [NFT_MSG_NEWOBJ] = AUDIT_NFT_OP_OBJ_REGISTER,
> > + [NFT_MSG_GETOBJ] = AUDIT_NFT_OP_INVALID,
> > + [NFT_MSG_DELOBJ] = AUDIT_NFT_OP_OBJ_UNREGISTER,
> > + [NFT_MSG_GETOBJ_RESET] = AUDIT_NFT_OP_OBJ_RESET,
> > + [NFT_MSG_NEWFLOWTABLE] = AUDIT_NFT_OP_FLOWTABLE_REGISTER,
> > + [NFT_MSG_GETFLOWTABLE] = AUDIT_NFT_OP_INVALID,
> > + [NFT_MSG_DELFLOWTABLE] = AUDIT_NFT_OP_FLOWTABLE_UNREGISTER,
> > +};
>
> The previously reported problem with this as a static still exists,
> correct? It does seem like this should live in nf_tables_api.c
> doesn't it?

Yes. Thank you.

> paul moore

- RGB

--
Richard Guy Briggs <rgb@xxxxxxxxxx>
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