Merge tag '6.1-rc-smb3-client-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6
[platform/kernel/linux-starfive.git] / security / lsm_audit.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * common LSM auditing functions
4  *
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>
9  */
10
11 #include <linux/types.h>
12 #include <linux/stddef.h>
13 #include <linux/kernel.h>
14 #include <linux/gfp.h>
15 #include <linux/fs.h>
16 #include <linux/init.h>
17 #include <net/sock.h>
18 #include <linux/un.h>
19 #include <net/af_unix.h>
20 #include <linux/audit.h>
21 #include <linux/ipv6.h>
22 #include <linux/ip.h>
23 #include <net/ip.h>
24 #include <net/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>
31
32 /**
33  * ipv4_skb_to_auditdata : fill auditdata from skb
34  * @skb : the skb
35  * @ad : the audit data to fill
36  * @proto : the layer 4 protocol
37  *
38  * return  0 on success
39  */
40 int ipv4_skb_to_auditdata(struct sk_buff *skb,
41                 struct common_audit_data *ad, u8 *proto)
42 {
43         int ret = 0;
44         struct iphdr *ih;
45
46         ih = ip_hdr(skb);
47         ad->u.net->v4info.saddr = ih->saddr;
48         ad->u.net->v4info.daddr = ih->daddr;
49
50         if (proto)
51                 *proto = ih->protocol;
52         /* non initial fragment */
53         if (ntohs(ih->frag_off) & IP_OFFSET)
54                 return 0;
55
56         switch (ih->protocol) {
57         case IPPROTO_TCP: {
58                 struct tcphdr *th = tcp_hdr(skb);
59
60                 ad->u.net->sport = th->source;
61                 ad->u.net->dport = th->dest;
62                 break;
63         }
64         case IPPROTO_UDP: {
65                 struct udphdr *uh = udp_hdr(skb);
66
67                 ad->u.net->sport = uh->source;
68                 ad->u.net->dport = uh->dest;
69                 break;
70         }
71         case IPPROTO_DCCP: {
72                 struct dccp_hdr *dh = dccp_hdr(skb);
73
74                 ad->u.net->sport = dh->dccph_sport;
75                 ad->u.net->dport = dh->dccph_dport;
76                 break;
77         }
78         case IPPROTO_SCTP: {
79                 struct sctphdr *sh = sctp_hdr(skb);
80
81                 ad->u.net->sport = sh->source;
82                 ad->u.net->dport = sh->dest;
83                 break;
84         }
85         default:
86                 ret = -EINVAL;
87         }
88         return ret;
89 }
90 #if IS_ENABLED(CONFIG_IPV6)
91 /**
92  * ipv6_skb_to_auditdata : fill auditdata from skb
93  * @skb : the skb
94  * @ad : the audit data to fill
95  * @proto : the layer 4 protocol
96  *
97  * return  0 on success
98  */
99 int ipv6_skb_to_auditdata(struct sk_buff *skb,
100                 struct common_audit_data *ad, u8 *proto)
101 {
102         int offset, ret = 0;
103         struct ipv6hdr *ip6;
104         u8 nexthdr;
105         __be16 frag_off;
106
107         ip6 = ipv6_hdr(skb);
108         ad->u.net->v6info.saddr = ip6->saddr;
109         ad->u.net->v6info.daddr = ip6->daddr;
110         /* IPv6 can have several extension header before the Transport header
111          * skip them */
112         offset = skb_network_offset(skb);
113         offset += sizeof(*ip6);
114         nexthdr = ip6->nexthdr;
115         offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
116         if (offset < 0)
117                 return 0;
118         if (proto)
119                 *proto = nexthdr;
120         switch (nexthdr) {
121         case IPPROTO_TCP: {
122                 struct tcphdr _tcph, *th;
123
124                 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
125                 if (th == NULL)
126                         break;
127
128                 ad->u.net->sport = th->source;
129                 ad->u.net->dport = th->dest;
130                 break;
131         }
132         case IPPROTO_UDP: {
133                 struct udphdr _udph, *uh;
134
135                 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
136                 if (uh == NULL)
137                         break;
138
139                 ad->u.net->sport = uh->source;
140                 ad->u.net->dport = uh->dest;
141                 break;
142         }
143         case IPPROTO_DCCP: {
144                 struct dccp_hdr _dccph, *dh;
145
146                 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
147                 if (dh == NULL)
148                         break;
149
150                 ad->u.net->sport = dh->dccph_sport;
151                 ad->u.net->dport = dh->dccph_dport;
152                 break;
153         }
154         case IPPROTO_SCTP: {
155                 struct sctphdr _sctph, *sh;
156
157                 sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
158                 if (sh == NULL)
159                         break;
160                 ad->u.net->sport = sh->source;
161                 ad->u.net->dport = sh->dest;
162                 break;
163         }
164         default:
165                 ret = -EINVAL;
166         }
167         return ret;
168 }
169 #endif
170
171
172 static inline void print_ipv6_addr(struct audit_buffer *ab,
173                                    const struct in6_addr *addr, __be16 port,
174                                    char *name1, char *name2)
175 {
176         if (!ipv6_addr_any(addr))
177                 audit_log_format(ab, " %s=%pI6c", name1, addr);
178         if (port)
179                 audit_log_format(ab, " %s=%d", name2, ntohs(port));
180 }
181
182 static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr,
183                                    __be16 port, char *name1, char *name2)
184 {
185         if (addr)
186                 audit_log_format(ab, " %s=%pI4", name1, &addr);
187         if (port)
188                 audit_log_format(ab, " %s=%d", name2, ntohs(port));
189 }
190
191 /**
192  * dump_common_audit_data - helper to dump common audit data
193  * @a : common audit data
194  *
195  */
196 static void dump_common_audit_data(struct audit_buffer *ab,
197                                    struct common_audit_data *a)
198 {
199         char comm[sizeof(current->comm)];
200
201         /*
202          * To keep stack sizes in check force programers to notice if they
203          * start making this union too large!  See struct lsm_network_audit
204          * as an example of how to deal with large data.
205          */
206         BUILD_BUG_ON(sizeof(a->u) > sizeof(void *)*2);
207
208         audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
209         audit_log_untrustedstring(ab, memcpy(comm, current->comm, sizeof(comm)));
210
211         switch (a->type) {
212         case LSM_AUDIT_DATA_NONE:
213                 return;
214         case LSM_AUDIT_DATA_IPC:
215                 audit_log_format(ab, " ipc_key=%d ", a->u.ipc_id);
216                 break;
217         case LSM_AUDIT_DATA_CAP:
218                 audit_log_format(ab, " capability=%d ", a->u.cap);
219                 break;
220         case LSM_AUDIT_DATA_PATH: {
221                 struct inode *inode;
222
223                 audit_log_d_path(ab, " path=", &a->u.path);
224
225                 inode = d_backing_inode(a->u.path.dentry);
226                 if (inode) {
227                         audit_log_format(ab, " dev=");
228                         audit_log_untrustedstring(ab, inode->i_sb->s_id);
229                         audit_log_format(ab, " ino=%lu", inode->i_ino);
230                 }
231                 break;
232         }
233         case LSM_AUDIT_DATA_FILE: {
234                 struct inode *inode;
235
236                 audit_log_d_path(ab, " path=", &a->u.file->f_path);
237
238                 inode = file_inode(a->u.file);
239                 if (inode) {
240                         audit_log_format(ab, " dev=");
241                         audit_log_untrustedstring(ab, inode->i_sb->s_id);
242                         audit_log_format(ab, " ino=%lu", inode->i_ino);
243                 }
244                 break;
245         }
246         case LSM_AUDIT_DATA_IOCTL_OP: {
247                 struct inode *inode;
248
249                 audit_log_d_path(ab, " path=", &a->u.op->path);
250
251                 inode = a->u.op->path.dentry->d_inode;
252                 if (inode) {
253                         audit_log_format(ab, " dev=");
254                         audit_log_untrustedstring(ab, inode->i_sb->s_id);
255                         audit_log_format(ab, " ino=%lu", inode->i_ino);
256                 }
257
258                 audit_log_format(ab, " ioctlcmd=0x%hx", a->u.op->cmd);
259                 break;
260         }
261         case LSM_AUDIT_DATA_DENTRY: {
262                 struct inode *inode;
263
264                 audit_log_format(ab, " name=");
265                 spin_lock(&a->u.dentry->d_lock);
266                 audit_log_untrustedstring(ab, a->u.dentry->d_name.name);
267                 spin_unlock(&a->u.dentry->d_lock);
268
269                 inode = d_backing_inode(a->u.dentry);
270                 if (inode) {
271                         audit_log_format(ab, " dev=");
272                         audit_log_untrustedstring(ab, inode->i_sb->s_id);
273                         audit_log_format(ab, " ino=%lu", inode->i_ino);
274                 }
275                 break;
276         }
277         case LSM_AUDIT_DATA_INODE: {
278                 struct dentry *dentry;
279                 struct inode *inode;
280
281                 rcu_read_lock();
282                 inode = a->u.inode;
283                 dentry = d_find_alias_rcu(inode);
284                 if (dentry) {
285                         audit_log_format(ab, " name=");
286                         spin_lock(&dentry->d_lock);
287                         audit_log_untrustedstring(ab, dentry->d_name.name);
288                         spin_unlock(&dentry->d_lock);
289                 }
290                 audit_log_format(ab, " dev=");
291                 audit_log_untrustedstring(ab, inode->i_sb->s_id);
292                 audit_log_format(ab, " ino=%lu", inode->i_ino);
293                 rcu_read_unlock();
294                 break;
295         }
296         case LSM_AUDIT_DATA_TASK: {
297                 struct task_struct *tsk = a->u.tsk;
298                 if (tsk) {
299                         pid_t pid = task_tgid_nr(tsk);
300                         if (pid) {
301                                 char comm[sizeof(tsk->comm)];
302                                 audit_log_format(ab, " opid=%d ocomm=", pid);
303                                 audit_log_untrustedstring(ab,
304                                     memcpy(comm, tsk->comm, sizeof(comm)));
305                         }
306                 }
307                 break;
308         }
309         case LSM_AUDIT_DATA_NET:
310                 if (a->u.net->sk) {
311                         const struct sock *sk = a->u.net->sk;
312                         struct unix_sock *u;
313                         struct unix_address *addr;
314                         int len = 0;
315                         char *p = NULL;
316
317                         switch (sk->sk_family) {
318                         case AF_INET: {
319                                 struct inet_sock *inet = inet_sk(sk);
320
321                                 print_ipv4_addr(ab, inet->inet_rcv_saddr,
322                                                 inet->inet_sport,
323                                                 "laddr", "lport");
324                                 print_ipv4_addr(ab, inet->inet_daddr,
325                                                 inet->inet_dport,
326                                                 "faddr", "fport");
327                                 break;
328                         }
329 #if IS_ENABLED(CONFIG_IPV6)
330                         case AF_INET6: {
331                                 struct inet_sock *inet = inet_sk(sk);
332
333                                 print_ipv6_addr(ab, &sk->sk_v6_rcv_saddr,
334                                                 inet->inet_sport,
335                                                 "laddr", "lport");
336                                 print_ipv6_addr(ab, &sk->sk_v6_daddr,
337                                                 inet->inet_dport,
338                                                 "faddr", "fport");
339                                 break;
340                         }
341 #endif
342                         case AF_UNIX:
343                                 u = unix_sk(sk);
344                                 addr = smp_load_acquire(&u->addr);
345                                 if (!addr)
346                                         break;
347                                 if (u->path.dentry) {
348                                         audit_log_d_path(ab, " path=", &u->path);
349                                         break;
350                                 }
351                                 len = addr->len-sizeof(short);
352                                 p = &addr->name->sun_path[0];
353                                 audit_log_format(ab, " path=");
354                                 if (*p)
355                                         audit_log_untrustedstring(ab, p);
356                                 else
357                                         audit_log_n_hex(ab, p, len);
358                                 break;
359                         }
360                 }
361
362                 switch (a->u.net->family) {
363                 case AF_INET:
364                         print_ipv4_addr(ab, a->u.net->v4info.saddr,
365                                         a->u.net->sport,
366                                         "saddr", "src");
367                         print_ipv4_addr(ab, a->u.net->v4info.daddr,
368                                         a->u.net->dport,
369                                         "daddr", "dest");
370                         break;
371                 case AF_INET6:
372                         print_ipv6_addr(ab, &a->u.net->v6info.saddr,
373                                         a->u.net->sport,
374                                         "saddr", "src");
375                         print_ipv6_addr(ab, &a->u.net->v6info.daddr,
376                                         a->u.net->dport,
377                                         "daddr", "dest");
378                         break;
379                 }
380                 if (a->u.net->netif > 0) {
381                         struct net_device *dev;
382
383                         /* NOTE: we always use init's namespace */
384                         dev = dev_get_by_index(&init_net, a->u.net->netif);
385                         if (dev) {
386                                 audit_log_format(ab, " netif=%s", dev->name);
387                                 dev_put(dev);
388                         }
389                 }
390                 break;
391 #ifdef CONFIG_KEYS
392         case LSM_AUDIT_DATA_KEY:
393                 audit_log_format(ab, " key_serial=%u", a->u.key_struct.key);
394                 if (a->u.key_struct.key_desc) {
395                         audit_log_format(ab, " key_desc=");
396                         audit_log_untrustedstring(ab, a->u.key_struct.key_desc);
397                 }
398                 break;
399 #endif
400         case LSM_AUDIT_DATA_KMOD:
401                 audit_log_format(ab, " kmod=");
402                 audit_log_untrustedstring(ab, a->u.kmod_name);
403                 break;
404         case LSM_AUDIT_DATA_IBPKEY: {
405                 struct in6_addr sbn_pfx;
406
407                 memset(&sbn_pfx.s6_addr, 0,
408                        sizeof(sbn_pfx.s6_addr));
409                 memcpy(&sbn_pfx.s6_addr, &a->u.ibpkey->subnet_prefix,
410                        sizeof(a->u.ibpkey->subnet_prefix));
411                 audit_log_format(ab, " pkey=0x%x subnet_prefix=%pI6c",
412                                  a->u.ibpkey->pkey, &sbn_pfx);
413                 break;
414         }
415         case LSM_AUDIT_DATA_IBENDPORT:
416                 audit_log_format(ab, " device=%s port_num=%u",
417                                  a->u.ibendport->dev_name,
418                                  a->u.ibendport->port);
419                 break;
420         case LSM_AUDIT_DATA_LOCKDOWN:
421                 audit_log_format(ab, " lockdown_reason=\"%s\"",
422                                  lockdown_reasons[a->u.reason]);
423                 break;
424         case LSM_AUDIT_DATA_ANONINODE:
425                 audit_log_format(ab, " anonclass=%s", a->u.anonclass);
426                 break;
427         } /* switch (a->type) */
428 }
429
430 /**
431  * common_lsm_audit - generic LSM auditing function
432  * @a:  auxiliary audit data
433  * @pre_audit: lsm-specific pre-audit callback
434  * @post_audit: lsm-specific post-audit callback
435  *
436  * setup the audit buffer for common security information
437  * uses callback to print LSM specific information
438  */
439 void common_lsm_audit(struct common_audit_data *a,
440         void (*pre_audit)(struct audit_buffer *, void *),
441         void (*post_audit)(struct audit_buffer *, void *))
442 {
443         struct audit_buffer *ab;
444
445         if (a == NULL)
446                 return;
447         /* we use GFP_ATOMIC so we won't sleep */
448         ab = audit_log_start(audit_context(), GFP_ATOMIC | __GFP_NOWARN,
449                              AUDIT_AVC);
450
451         if (ab == NULL)
452                 return;
453
454         if (pre_audit)
455                 pre_audit(ab, a);
456
457         dump_common_audit_data(ab, a);
458
459         if (post_audit)
460                 post_audit(ab, a);
461
462         audit_log_end(ab);
463 }