1 // SPDX-License-Identifier: GPL-2.0-only
3 * common LSM auditing functions
5 * Based on code written for SELinux by :
6 * Stephen Smalley, <sds@tycho.nsa.gov>
7 * James Morris <jmorris@redhat.com>
8 * Author : Etienne Basset, <etienne.basset@ensta.org>
11 #include <linux/types.h>
12 #include <linux/stddef.h>
13 #include <linux/kernel.h>
14 #include <linux/gfp.h>
16 #include <linux/init.h>
19 #include <net/af_unix.h>
20 #include <linux/audit.h>
21 #include <linux/ipv6.h>
25 #include <linux/tcp.h>
26 #include <linux/udp.h>
27 #include <linux/dccp.h>
28 #include <linux/sctp.h>
29 #include <linux/lsm_audit.h>
30 #include <linux/security.h>
33 * ipv4_skb_to_auditdata : fill auditdata from skb
35 * @ad : the audit data to fill
36 * @proto : the layer 4 protocol
40 int ipv4_skb_to_auditdata(struct sk_buff *skb,
41 struct common_audit_data *ad, u8 *proto)
50 ad->u.net->v4info.saddr = ih->saddr;
51 ad->u.net->v4info.daddr = ih->daddr;
54 *proto = ih->protocol;
55 /* non initial fragment */
56 if (ntohs(ih->frag_off) & IP_OFFSET)
59 switch (ih->protocol) {
61 struct tcphdr *th = tcp_hdr(skb);
65 ad->u.net->sport = th->source;
66 ad->u.net->dport = th->dest;
70 struct udphdr *uh = udp_hdr(skb);
74 ad->u.net->sport = uh->source;
75 ad->u.net->dport = uh->dest;
79 struct dccp_hdr *dh = dccp_hdr(skb);
83 ad->u.net->sport = dh->dccph_sport;
84 ad->u.net->dport = dh->dccph_dport;
88 struct sctphdr *sh = sctp_hdr(skb);
91 ad->u.net->sport = sh->source;
92 ad->u.net->dport = sh->dest;
100 #if IS_ENABLED(CONFIG_IPV6)
102 * ipv6_skb_to_auditdata : fill auditdata from skb
104 * @ad : the audit data to fill
105 * @proto : the layer 4 protocol
107 * return 0 on success
109 int ipv6_skb_to_auditdata(struct sk_buff *skb,
110 struct common_audit_data *ad, u8 *proto)
120 ad->u.net->v6info.saddr = ip6->saddr;
121 ad->u.net->v6info.daddr = ip6->daddr;
122 /* IPv6 can have several extension header before the Transport header
124 offset = skb_network_offset(skb);
125 offset += sizeof(*ip6);
126 nexthdr = ip6->nexthdr;
127 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
134 struct tcphdr _tcph, *th;
136 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
140 ad->u.net->sport = th->source;
141 ad->u.net->dport = th->dest;
145 struct udphdr _udph, *uh;
147 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
151 ad->u.net->sport = uh->source;
152 ad->u.net->dport = uh->dest;
156 struct dccp_hdr _dccph, *dh;
158 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
162 ad->u.net->sport = dh->dccph_sport;
163 ad->u.net->dport = dh->dccph_dport;
167 struct sctphdr _sctph, *sh;
169 sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
172 ad->u.net->sport = sh->source;
173 ad->u.net->dport = sh->dest;
184 static inline void print_ipv6_addr(struct audit_buffer *ab,
185 const struct in6_addr *addr, __be16 port,
186 char *name1, char *name2)
188 if (!ipv6_addr_any(addr))
189 audit_log_format(ab, " %s=%pI6c", name1, addr);
191 audit_log_format(ab, " %s=%d", name2, ntohs(port));
194 static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr,
195 __be16 port, char *name1, char *name2)
198 audit_log_format(ab, " %s=%pI4", name1, &addr);
200 audit_log_format(ab, " %s=%d", name2, ntohs(port));
204 * dump_common_audit_data - helper to dump common audit data
205 * @a : common audit data
208 static void dump_common_audit_data(struct audit_buffer *ab,
209 struct common_audit_data *a)
211 char comm[sizeof(current->comm)];
214 * To keep stack sizes in check force programers to notice if they
215 * start making this union too large! See struct lsm_network_audit
216 * as an example of how to deal with large data.
218 BUILD_BUG_ON(sizeof(a->u) > sizeof(void *)*2);
220 audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
221 audit_log_untrustedstring(ab, memcpy(comm, current->comm, sizeof(comm)));
224 case LSM_AUDIT_DATA_NONE:
226 case LSM_AUDIT_DATA_IPC:
227 audit_log_format(ab, " ipc_key=%d ", a->u.ipc_id);
229 case LSM_AUDIT_DATA_CAP:
230 audit_log_format(ab, " capability=%d ", a->u.cap);
232 case LSM_AUDIT_DATA_PATH: {
235 audit_log_d_path(ab, " path=", &a->u.path);
237 inode = d_backing_inode(a->u.path.dentry);
239 audit_log_format(ab, " dev=");
240 audit_log_untrustedstring(ab, inode->i_sb->s_id);
241 audit_log_format(ab, " ino=%lu", inode->i_ino);
245 case LSM_AUDIT_DATA_FILE: {
248 audit_log_d_path(ab, " path=", &a->u.file->f_path);
250 inode = file_inode(a->u.file);
252 audit_log_format(ab, " dev=");
253 audit_log_untrustedstring(ab, inode->i_sb->s_id);
254 audit_log_format(ab, " ino=%lu", inode->i_ino);
258 case LSM_AUDIT_DATA_IOCTL_OP: {
261 audit_log_d_path(ab, " path=", &a->u.op->path);
263 inode = a->u.op->path.dentry->d_inode;
265 audit_log_format(ab, " dev=");
266 audit_log_untrustedstring(ab, inode->i_sb->s_id);
267 audit_log_format(ab, " ino=%lu", inode->i_ino);
270 audit_log_format(ab, " ioctlcmd=0x%hx", a->u.op->cmd);
273 case LSM_AUDIT_DATA_DENTRY: {
276 audit_log_format(ab, " name=");
277 spin_lock(&a->u.dentry->d_lock);
278 audit_log_untrustedstring(ab, a->u.dentry->d_name.name);
279 spin_unlock(&a->u.dentry->d_lock);
281 inode = d_backing_inode(a->u.dentry);
283 audit_log_format(ab, " dev=");
284 audit_log_untrustedstring(ab, inode->i_sb->s_id);
285 audit_log_format(ab, " ino=%lu", inode->i_ino);
289 case LSM_AUDIT_DATA_INODE: {
290 struct dentry *dentry;
295 dentry = d_find_alias_rcu(inode);
297 audit_log_format(ab, " name=");
298 spin_lock(&dentry->d_lock);
299 audit_log_untrustedstring(ab, dentry->d_name.name);
300 spin_unlock(&dentry->d_lock);
302 audit_log_format(ab, " dev=");
303 audit_log_untrustedstring(ab, inode->i_sb->s_id);
304 audit_log_format(ab, " ino=%lu", inode->i_ino);
308 case LSM_AUDIT_DATA_TASK: {
309 struct task_struct *tsk = a->u.tsk;
311 pid_t pid = task_tgid_nr(tsk);
313 char comm[sizeof(tsk->comm)];
314 audit_log_format(ab, " opid=%d ocomm=", pid);
315 audit_log_untrustedstring(ab,
316 memcpy(comm, tsk->comm, sizeof(comm)));
321 case LSM_AUDIT_DATA_NET:
323 const struct sock *sk = a->u.net->sk;
325 struct unix_address *addr;
329 switch (sk->sk_family) {
331 struct inet_sock *inet = inet_sk(sk);
333 print_ipv4_addr(ab, inet->inet_rcv_saddr,
336 print_ipv4_addr(ab, inet->inet_daddr,
341 #if IS_ENABLED(CONFIG_IPV6)
343 struct inet_sock *inet = inet_sk(sk);
345 print_ipv6_addr(ab, &sk->sk_v6_rcv_saddr,
348 print_ipv6_addr(ab, &sk->sk_v6_daddr,
356 addr = smp_load_acquire(&u->addr);
359 if (u->path.dentry) {
360 audit_log_d_path(ab, " path=", &u->path);
363 len = addr->len-sizeof(short);
364 p = &addr->name->sun_path[0];
365 audit_log_format(ab, " path=");
367 audit_log_untrustedstring(ab, p);
369 audit_log_n_hex(ab, p, len);
374 switch (a->u.net->family) {
376 print_ipv4_addr(ab, a->u.net->v4info.saddr,
379 print_ipv4_addr(ab, a->u.net->v4info.daddr,
384 print_ipv6_addr(ab, &a->u.net->v6info.saddr,
387 print_ipv6_addr(ab, &a->u.net->v6info.daddr,
392 if (a->u.net->netif > 0) {
393 struct net_device *dev;
395 /* NOTE: we always use init's namespace */
396 dev = dev_get_by_index(&init_net, a->u.net->netif);
398 audit_log_format(ab, " netif=%s", dev->name);
404 case LSM_AUDIT_DATA_KEY:
405 audit_log_format(ab, " key_serial=%u", a->u.key_struct.key);
406 if (a->u.key_struct.key_desc) {
407 audit_log_format(ab, " key_desc=");
408 audit_log_untrustedstring(ab, a->u.key_struct.key_desc);
412 case LSM_AUDIT_DATA_KMOD:
413 audit_log_format(ab, " kmod=");
414 audit_log_untrustedstring(ab, a->u.kmod_name);
416 case LSM_AUDIT_DATA_IBPKEY: {
417 struct in6_addr sbn_pfx;
419 memset(&sbn_pfx.s6_addr, 0,
420 sizeof(sbn_pfx.s6_addr));
421 memcpy(&sbn_pfx.s6_addr, &a->u.ibpkey->subnet_prefix,
422 sizeof(a->u.ibpkey->subnet_prefix));
423 audit_log_format(ab, " pkey=0x%x subnet_prefix=%pI6c",
424 a->u.ibpkey->pkey, &sbn_pfx);
427 case LSM_AUDIT_DATA_IBENDPORT:
428 audit_log_format(ab, " device=%s port_num=%u",
429 a->u.ibendport->dev_name,
430 a->u.ibendport->port);
432 case LSM_AUDIT_DATA_LOCKDOWN:
433 audit_log_format(ab, " lockdown_reason=\"%s\"",
434 lockdown_reasons[a->u.reason]);
436 } /* switch (a->type) */
440 * common_lsm_audit - generic LSM auditing function
441 * @a: auxiliary audit data
442 * @pre_audit: lsm-specific pre-audit callback
443 * @post_audit: lsm-specific post-audit callback
445 * setup the audit buffer for common security information
446 * uses callback to print LSM specific information
448 void common_lsm_audit(struct common_audit_data *a,
449 void (*pre_audit)(struct audit_buffer *, void *),
450 void (*post_audit)(struct audit_buffer *, void *))
452 struct audit_buffer *ab;
456 /* we use GFP_ATOMIC so we won't sleep */
457 ab = audit_log_start(audit_context(), GFP_ATOMIC | __GFP_NOWARN,
466 dump_common_audit_data(ab, a);