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

[Richard Guy Briggs]

On 2021-03-24 12:32, Paul Moore wrote:
> On Tue, Mar 23, 2021 at 4:05 PM Richard Guy Briggs <rgb at redhat.com> 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 at redhat.com>
> > ---
> > 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 at redhat.com>
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