Merge tag 'dma-mapping-6.7-2023-11-10' of git://git.infradead.org/users/hch/dma-mapping
[linux-2.6-microblaze.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  * @ab : the audit buffer
194  * @a : common audit data
195  *
196  */
197 static void dump_common_audit_data(struct audit_buffer *ab,
198                                    struct common_audit_data *a)
199 {
200         char comm[sizeof(current->comm)];
201
202         /*
203          * To keep stack sizes in check force programmers to notice if they
204          * start making this union too large!  See struct lsm_network_audit
205          * as an example of how to deal with large data.
206          */
207         BUILD_BUG_ON(sizeof(a->u) > sizeof(void *)*2);
208
209         audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
210         audit_log_untrustedstring(ab, memcpy(comm, current->comm, sizeof(comm)));
211
212         switch (a->type) {
213         case LSM_AUDIT_DATA_NONE:
214                 return;
215         case LSM_AUDIT_DATA_IPC:
216                 audit_log_format(ab, " ipc_key=%d ", a->u.ipc_id);
217                 break;
218         case LSM_AUDIT_DATA_CAP:
219                 audit_log_format(ab, " capability=%d ", a->u.cap);
220                 break;
221         case LSM_AUDIT_DATA_PATH: {
222                 struct inode *inode;
223
224                 audit_log_d_path(ab, " path=", &a->u.path);
225
226                 inode = d_backing_inode(a->u.path.dentry);
227                 if (inode) {
228                         audit_log_format(ab, " dev=");
229                         audit_log_untrustedstring(ab, inode->i_sb->s_id);
230                         audit_log_format(ab, " ino=%lu", inode->i_ino);
231                 }
232                 break;
233         }
234         case LSM_AUDIT_DATA_FILE: {
235                 struct inode *inode;
236
237                 audit_log_d_path(ab, " path=", &a->u.file->f_path);
238
239                 inode = file_inode(a->u.file);
240                 if (inode) {
241                         audit_log_format(ab, " dev=");
242                         audit_log_untrustedstring(ab, inode->i_sb->s_id);
243                         audit_log_format(ab, " ino=%lu", inode->i_ino);
244                 }
245                 break;
246         }
247         case LSM_AUDIT_DATA_IOCTL_OP: {
248                 struct inode *inode;
249
250                 audit_log_d_path(ab, " path=", &a->u.op->path);
251
252                 inode = a->u.op->path.dentry->d_inode;
253                 if (inode) {
254                         audit_log_format(ab, " dev=");
255                         audit_log_untrustedstring(ab, inode->i_sb->s_id);
256                         audit_log_format(ab, " ino=%lu", inode->i_ino);
257                 }
258
259                 audit_log_format(ab, " ioctlcmd=0x%hx", a->u.op->cmd);
260                 break;
261         }
262         case LSM_AUDIT_DATA_DENTRY: {
263                 struct inode *inode;
264
265                 audit_log_format(ab, " name=");
266                 spin_lock(&a->u.dentry->d_lock);
267                 audit_log_untrustedstring(ab, a->u.dentry->d_name.name);
268                 spin_unlock(&a->u.dentry->d_lock);
269
270                 inode = d_backing_inode(a->u.dentry);
271                 if (inode) {
272                         audit_log_format(ab, " dev=");
273                         audit_log_untrustedstring(ab, inode->i_sb->s_id);
274                         audit_log_format(ab, " ino=%lu", inode->i_ino);
275                 }
276                 break;
277         }
278         case LSM_AUDIT_DATA_INODE: {
279                 struct dentry *dentry;
280                 struct inode *inode;
281
282                 rcu_read_lock();
283                 inode = a->u.inode;
284                 dentry = d_find_alias_rcu(inode);
285                 if (dentry) {
286                         audit_log_format(ab, " name=");
287                         spin_lock(&dentry->d_lock);
288                         audit_log_untrustedstring(ab, dentry->d_name.name);
289                         spin_unlock(&dentry->d_lock);
290                 }
291                 audit_log_format(ab, " dev=");
292                 audit_log_untrustedstring(ab, inode->i_sb->s_id);
293                 audit_log_format(ab, " ino=%lu", inode->i_ino);
294                 rcu_read_unlock();
295                 break;
296         }
297         case LSM_AUDIT_DATA_TASK: {
298                 struct task_struct *tsk = a->u.tsk;
299                 if (tsk) {
300                         pid_t pid = task_tgid_nr(tsk);
301                         if (pid) {
302                                 char comm[sizeof(tsk->comm)];
303                                 audit_log_format(ab, " opid=%d ocomm=", pid);
304                                 audit_log_untrustedstring(ab,
305                                     memcpy(comm, tsk->comm, sizeof(comm)));
306                         }
307                 }
308                 break;
309         }
310         case LSM_AUDIT_DATA_NET:
311                 if (a->u.net->sk) {
312                         const struct sock *sk = a->u.net->sk;
313                         const struct unix_sock *u;
314                         struct unix_address *addr;
315                         int len = 0;
316                         char *p = NULL;
317
318                         switch (sk->sk_family) {
319                         case AF_INET: {
320                                 const struct inet_sock *inet = inet_sk(sk);
321
322                                 print_ipv4_addr(ab, inet->inet_rcv_saddr,
323                                                 inet->inet_sport,
324                                                 "laddr", "lport");
325                                 print_ipv4_addr(ab, inet->inet_daddr,
326                                                 inet->inet_dport,
327                                                 "faddr", "fport");
328                                 break;
329                         }
330 #if IS_ENABLED(CONFIG_IPV6)
331                         case AF_INET6: {
332                                 const struct inet_sock *inet = inet_sk(sk);
333
334                                 print_ipv6_addr(ab, &sk->sk_v6_rcv_saddr,
335                                                 inet->inet_sport,
336                                                 "laddr", "lport");
337                                 print_ipv6_addr(ab, &sk->sk_v6_daddr,
338                                                 inet->inet_dport,
339                                                 "faddr", "fport");
340                                 break;
341                         }
342 #endif
343                         case AF_UNIX:
344                                 u = unix_sk(sk);
345                                 addr = smp_load_acquire(&u->addr);
346                                 if (!addr)
347                                         break;
348                                 if (u->path.dentry) {
349                                         audit_log_d_path(ab, " path=", &u->path);
350                                         break;
351                                 }
352                                 len = addr->len-sizeof(short);
353                                 p = &addr->name->sun_path[0];
354                                 audit_log_format(ab, " path=");
355                                 if (*p)
356                                         audit_log_untrustedstring(ab, p);
357                                 else
358                                         audit_log_n_hex(ab, p, len);
359                                 break;
360                         }
361                 }
362
363                 switch (a->u.net->family) {
364                 case AF_INET:
365                         print_ipv4_addr(ab, a->u.net->v4info.saddr,
366                                         a->u.net->sport,
367                                         "saddr", "src");
368                         print_ipv4_addr(ab, a->u.net->v4info.daddr,
369                                         a->u.net->dport,
370                                         "daddr", "dest");
371                         break;
372                 case AF_INET6:
373                         print_ipv6_addr(ab, &a->u.net->v6info.saddr,
374                                         a->u.net->sport,
375                                         "saddr", "src");
376                         print_ipv6_addr(ab, &a->u.net->v6info.daddr,
377                                         a->u.net->dport,
378                                         "daddr", "dest");
379                         break;
380                 }
381                 if (a->u.net->netif > 0) {
382                         struct net_device *dev;
383
384                         /* NOTE: we always use init's namespace */
385                         dev = dev_get_by_index(&init_net, a->u.net->netif);
386                         if (dev) {
387                                 audit_log_format(ab, " netif=%s", dev->name);
388                                 dev_put(dev);
389                         }
390                 }
391                 break;
392 #ifdef CONFIG_KEYS
393         case LSM_AUDIT_DATA_KEY:
394                 audit_log_format(ab, " key_serial=%u", a->u.key_struct.key);
395                 if (a->u.key_struct.key_desc) {
396                         audit_log_format(ab, " key_desc=");
397                         audit_log_untrustedstring(ab, a->u.key_struct.key_desc);
398                 }
399                 break;
400 #endif
401         case LSM_AUDIT_DATA_KMOD:
402                 audit_log_format(ab, " kmod=");
403                 audit_log_untrustedstring(ab, a->u.kmod_name);
404                 break;
405         case LSM_AUDIT_DATA_IBPKEY: {
406                 struct in6_addr sbn_pfx;
407
408                 memset(&sbn_pfx.s6_addr, 0,
409                        sizeof(sbn_pfx.s6_addr));
410                 memcpy(&sbn_pfx.s6_addr, &a->u.ibpkey->subnet_prefix,
411                        sizeof(a->u.ibpkey->subnet_prefix));
412                 audit_log_format(ab, " pkey=0x%x subnet_prefix=%pI6c",
413                                  a->u.ibpkey->pkey, &sbn_pfx);
414                 break;
415         }
416         case LSM_AUDIT_DATA_IBENDPORT:
417                 audit_log_format(ab, " device=%s port_num=%u",
418                                  a->u.ibendport->dev_name,
419                                  a->u.ibendport->port);
420                 break;
421         case LSM_AUDIT_DATA_LOCKDOWN:
422                 audit_log_format(ab, " lockdown_reason=\"%s\"",
423                                  lockdown_reasons[a->u.reason]);
424                 break;
425         case LSM_AUDIT_DATA_ANONINODE:
426                 audit_log_format(ab, " anonclass=%s", a->u.anonclass);
427                 break;
428         } /* switch (a->type) */
429 }
430
431 /**
432  * common_lsm_audit - generic LSM auditing function
433  * @a:  auxiliary audit data
434  * @pre_audit: lsm-specific pre-audit callback
435  * @post_audit: lsm-specific post-audit callback
436  *
437  * setup the audit buffer for common security information
438  * uses callback to print LSM specific information
439  */
440 void common_lsm_audit(struct common_audit_data *a,
441         void (*pre_audit)(struct audit_buffer *, void *),
442         void (*post_audit)(struct audit_buffer *, void *))
443 {
444         struct audit_buffer *ab;
445
446         if (a == NULL)
447                 return;
448         /* we use GFP_ATOMIC so we won't sleep */
449         ab = audit_log_start(audit_context(), GFP_ATOMIC | __GFP_NOWARN,
450                              AUDIT_AVC);
451
452         if (ab == NULL)
453                 return;
454
455         if (pre_audit)
456                 pre_audit(ab, a);
457
458         dump_common_audit_data(ab, a);
459
460         if (post_audit)
461                 post_audit(ab, a);
462
463         audit_log_end(ab);
464 }