| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * common LSM auditing functions |
| * |
| * Based on code written for SELinux by : |
| * Stephen Smalley, <sds@tycho.nsa.gov> |
| * James Morris <jmorris@redhat.com> |
| * Author : Etienne Basset, <etienne.basset@ensta.org> |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/stddef.h> |
| #include <linux/kernel.h> |
| #include <linux/gfp.h> |
| #include <linux/fs.h> |
| #include <linux/init.h> |
| #include <net/sock.h> |
| #include <linux/un.h> |
| #include <net/af_unix.h> |
| #include <linux/audit.h> |
| #include <linux/ipv6.h> |
| #include <linux/ip.h> |
| #include <net/ip.h> |
| #include <net/ipv6.h> |
| #include <linux/tcp.h> |
| #include <linux/udp.h> |
| #include <linux/dccp.h> |
| #include <linux/sctp.h> |
| #include <linux/lsm_audit.h> |
| #include <linux/security.h> |
| |
| /** |
| * ipv4_skb_to_auditdata : fill auditdata from skb |
| * @skb : the skb |
| * @ad : the audit data to fill |
| * @proto : the layer 4 protocol |
| * |
| * return 0 on success |
| */ |
| int ipv4_skb_to_auditdata(struct sk_buff *skb, |
| struct common_audit_data *ad, u8 *proto) |
| { |
| int ret = 0; |
| struct iphdr *ih; |
| |
| ih = ip_hdr(skb); |
| ad->u.net->v4info.saddr = ih->saddr; |
| ad->u.net->v4info.daddr = ih->daddr; |
| |
| if (proto) |
| *proto = ih->protocol; |
| /* non initial fragment */ |
| if (ntohs(ih->frag_off) & IP_OFFSET) |
| return 0; |
| |
| switch (ih->protocol) { |
| case IPPROTO_TCP: { |
| struct tcphdr *th = tcp_hdr(skb); |
| |
| ad->u.net->sport = th->source; |
| ad->u.net->dport = th->dest; |
| break; |
| } |
| case IPPROTO_UDP: { |
| struct udphdr *uh = udp_hdr(skb); |
| |
| ad->u.net->sport = uh->source; |
| ad->u.net->dport = uh->dest; |
| break; |
| } |
| case IPPROTO_DCCP: { |
| struct dccp_hdr *dh = dccp_hdr(skb); |
| |
| ad->u.net->sport = dh->dccph_sport; |
| ad->u.net->dport = dh->dccph_dport; |
| break; |
| } |
| case IPPROTO_SCTP: { |
| struct sctphdr *sh = sctp_hdr(skb); |
| |
| ad->u.net->sport = sh->source; |
| ad->u.net->dport = sh->dest; |
| break; |
| } |
| default: |
| ret = -EINVAL; |
| } |
| return ret; |
| } |
| #if IS_ENABLED(CONFIG_IPV6) |
| /** |
| * ipv6_skb_to_auditdata : fill auditdata from skb |
| * @skb : the skb |
| * @ad : the audit data to fill |
| * @proto : the layer 4 protocol |
| * |
| * return 0 on success |
| */ |
| int ipv6_skb_to_auditdata(struct sk_buff *skb, |
| struct common_audit_data *ad, u8 *proto) |
| { |
| int offset, ret = 0; |
| struct ipv6hdr *ip6; |
| u8 nexthdr; |
| __be16 frag_off; |
| |
| ip6 = ipv6_hdr(skb); |
| ad->u.net->v6info.saddr = ip6->saddr; |
| ad->u.net->v6info.daddr = ip6->daddr; |
| /* IPv6 can have several extension header before the Transport header |
| * skip them */ |
| offset = skb_network_offset(skb); |
| offset += sizeof(*ip6); |
| nexthdr = ip6->nexthdr; |
| offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); |
| if (offset < 0) |
| return 0; |
| if (proto) |
| *proto = nexthdr; |
| switch (nexthdr) { |
| case IPPROTO_TCP: { |
| struct tcphdr _tcph, *th; |
| |
| th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); |
| if (th == NULL) |
| break; |
| |
| ad->u.net->sport = th->source; |
| ad->u.net->dport = th->dest; |
| break; |
| } |
| case IPPROTO_UDP: { |
| struct udphdr _udph, *uh; |
| |
| uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); |
| if (uh == NULL) |
| break; |
| |
| ad->u.net->sport = uh->source; |
| ad->u.net->dport = uh->dest; |
| break; |
| } |
| case IPPROTO_DCCP: { |
| struct dccp_hdr _dccph, *dh; |
| |
| dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); |
| if (dh == NULL) |
| break; |
| |
| ad->u.net->sport = dh->dccph_sport; |
| ad->u.net->dport = dh->dccph_dport; |
| break; |
| } |
| case IPPROTO_SCTP: { |
| struct sctphdr _sctph, *sh; |
| |
| sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph); |
| if (sh == NULL) |
| break; |
| ad->u.net->sport = sh->source; |
| ad->u.net->dport = sh->dest; |
| break; |
| } |
| default: |
| ret = -EINVAL; |
| } |
| return ret; |
| } |
| #endif |
| |
| |
| static inline void print_ipv6_addr(struct audit_buffer *ab, |
| const struct in6_addr *addr, __be16 port, |
| char *name1, char *name2) |
| { |
| if (!ipv6_addr_any(addr)) |
| audit_log_format(ab, " %s=%pI6c", name1, addr); |
| if (port) |
| audit_log_format(ab, " %s=%d", name2, ntohs(port)); |
| } |
| |
| static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr, |
| __be16 port, char *name1, char *name2) |
| { |
| if (addr) |
| audit_log_format(ab, " %s=%pI4", name1, &addr); |
| if (port) |
| audit_log_format(ab, " %s=%d", name2, ntohs(port)); |
| } |
| |
| /** |
| * dump_common_audit_data - helper to dump common audit data |
| * @ab : the audit buffer |
| * @a : common audit data |
| * |
| */ |
| static void dump_common_audit_data(struct audit_buffer *ab, |
| struct common_audit_data *a) |
| { |
| char comm[sizeof(current->comm)]; |
| |
| /* |
| * To keep stack sizes in check force programmers to notice if they |
| * start making this union too large! See struct lsm_network_audit |
| * as an example of how to deal with large data. |
| */ |
| BUILD_BUG_ON(sizeof(a->u) > sizeof(void *)*2); |
| |
| audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current)); |
| audit_log_untrustedstring(ab, get_task_comm(comm, current)); |
| |
| switch (a->type) { |
| case LSM_AUDIT_DATA_NONE: |
| return; |
| case LSM_AUDIT_DATA_IPC: |
| audit_log_format(ab, " ipc_key=%d ", a->u.ipc_id); |
| break; |
| case LSM_AUDIT_DATA_CAP: |
| audit_log_format(ab, " capability=%d ", a->u.cap); |
| break; |
| case LSM_AUDIT_DATA_PATH: { |
| struct inode *inode; |
| |
| audit_log_d_path(ab, " path=", &a->u.path); |
| |
| inode = d_backing_inode(a->u.path.dentry); |
| if (inode) { |
| audit_log_format(ab, " dev="); |
| audit_log_untrustedstring(ab, inode->i_sb->s_id); |
| audit_log_format(ab, " ino=%lu", inode->i_ino); |
| } |
| break; |
| } |
| case LSM_AUDIT_DATA_FILE: { |
| struct inode *inode; |
| |
| audit_log_d_path(ab, " path=", &a->u.file->f_path); |
| |
| inode = file_inode(a->u.file); |
| if (inode) { |
| audit_log_format(ab, " dev="); |
| audit_log_untrustedstring(ab, inode->i_sb->s_id); |
| audit_log_format(ab, " ino=%lu", inode->i_ino); |
| } |
| break; |
| } |
| case LSM_AUDIT_DATA_IOCTL_OP: { |
| struct inode *inode; |
| |
| audit_log_d_path(ab, " path=", &a->u.op->path); |
| |
| inode = a->u.op->path.dentry->d_inode; |
| if (inode) { |
| audit_log_format(ab, " dev="); |
| audit_log_untrustedstring(ab, inode->i_sb->s_id); |
| audit_log_format(ab, " ino=%lu", inode->i_ino); |
| } |
| |
| audit_log_format(ab, " ioctlcmd=0x%hx", a->u.op->cmd); |
| break; |
| } |
| case LSM_AUDIT_DATA_DENTRY: { |
| struct inode *inode; |
| |
| audit_log_format(ab, " name="); |
| spin_lock(&a->u.dentry->d_lock); |
| audit_log_untrustedstring(ab, a->u.dentry->d_name.name); |
| spin_unlock(&a->u.dentry->d_lock); |
| |
| inode = d_backing_inode(a->u.dentry); |
| if (inode) { |
| audit_log_format(ab, " dev="); |
| audit_log_untrustedstring(ab, inode->i_sb->s_id); |
| audit_log_format(ab, " ino=%lu", inode->i_ino); |
| } |
| break; |
| } |
| case LSM_AUDIT_DATA_INODE: { |
| struct dentry *dentry; |
| struct inode *inode; |
| |
| rcu_read_lock(); |
| inode = a->u.inode; |
| dentry = d_find_alias_rcu(inode); |
| if (dentry) { |
| audit_log_format(ab, " name="); |
| spin_lock(&dentry->d_lock); |
| audit_log_untrustedstring(ab, dentry->d_name.name); |
| spin_unlock(&dentry->d_lock); |
| } |
| audit_log_format(ab, " dev="); |
| audit_log_untrustedstring(ab, inode->i_sb->s_id); |
| audit_log_format(ab, " ino=%lu", inode->i_ino); |
| rcu_read_unlock(); |
| break; |
| } |
| case LSM_AUDIT_DATA_TASK: { |
| struct task_struct *tsk = a->u.tsk; |
| if (tsk) { |
| pid_t pid = task_tgid_nr(tsk); |
| if (pid) { |
| char comm[sizeof(tsk->comm)]; |
| audit_log_format(ab, " opid=%d ocomm=", pid); |
| audit_log_untrustedstring(ab, |
| get_task_comm(comm, tsk)); |
| } |
| } |
| break; |
| } |
| case LSM_AUDIT_DATA_NET: |
| if (a->u.net->sk) { |
| const struct sock *sk = a->u.net->sk; |
| const struct unix_sock *u; |
| struct unix_address *addr; |
| int len = 0; |
| char *p = NULL; |
| |
| switch (sk->sk_family) { |
| case AF_INET: { |
| const struct inet_sock *inet = inet_sk(sk); |
| |
| print_ipv4_addr(ab, inet->inet_rcv_saddr, |
| inet->inet_sport, |
| "laddr", "lport"); |
| print_ipv4_addr(ab, inet->inet_daddr, |
| inet->inet_dport, |
| "faddr", "fport"); |
| break; |
| } |
| #if IS_ENABLED(CONFIG_IPV6) |
| case AF_INET6: { |
| const struct inet_sock *inet = inet_sk(sk); |
| |
| print_ipv6_addr(ab, &sk->sk_v6_rcv_saddr, |
| inet->inet_sport, |
| "laddr", "lport"); |
| print_ipv6_addr(ab, &sk->sk_v6_daddr, |
| inet->inet_dport, |
| "faddr", "fport"); |
| break; |
| } |
| #endif |
| case AF_UNIX: |
| u = unix_sk(sk); |
| addr = smp_load_acquire(&u->addr); |
| if (!addr) |
| break; |
| if (u->path.dentry) { |
| audit_log_d_path(ab, " path=", &u->path); |
| break; |
| } |
| len = addr->len-sizeof(short); |
| p = &addr->name->sun_path[0]; |
| audit_log_format(ab, " path="); |
| if (*p) |
| audit_log_untrustedstring(ab, p); |
| else |
| audit_log_n_hex(ab, p, len); |
| break; |
| } |
| } |
| |
| switch (a->u.net->family) { |
| case AF_INET: |
| print_ipv4_addr(ab, a->u.net->v4info.saddr, |
| a->u.net->sport, |
| "saddr", "src"); |
| print_ipv4_addr(ab, a->u.net->v4info.daddr, |
| a->u.net->dport, |
| "daddr", "dest"); |
| break; |
| case AF_INET6: |
| print_ipv6_addr(ab, &a->u.net->v6info.saddr, |
| a->u.net->sport, |
| "saddr", "src"); |
| print_ipv6_addr(ab, &a->u.net->v6info.daddr, |
| a->u.net->dport, |
| "daddr", "dest"); |
| break; |
| } |
| if (a->u.net->netif > 0) { |
| struct net_device *dev; |
| |
| /* NOTE: we always use init's namespace */ |
| dev = dev_get_by_index(&init_net, a->u.net->netif); |
| if (dev) { |
| audit_log_format(ab, " netif=%s", dev->name); |
| dev_put(dev); |
| } |
| } |
| break; |
| #ifdef CONFIG_KEYS |
| case LSM_AUDIT_DATA_KEY: |
| audit_log_format(ab, " key_serial=%u", a->u.key_struct.key); |
| if (a->u.key_struct.key_desc) { |
| audit_log_format(ab, " key_desc="); |
| audit_log_untrustedstring(ab, a->u.key_struct.key_desc); |
| } |
| break; |
| #endif |
| case LSM_AUDIT_DATA_KMOD: |
| audit_log_format(ab, " kmod="); |
| audit_log_untrustedstring(ab, a->u.kmod_name); |
| break; |
| case LSM_AUDIT_DATA_IBPKEY: { |
| struct in6_addr sbn_pfx; |
| |
| memset(&sbn_pfx.s6_addr, 0, |
| sizeof(sbn_pfx.s6_addr)); |
| memcpy(&sbn_pfx.s6_addr, &a->u.ibpkey->subnet_prefix, |
| sizeof(a->u.ibpkey->subnet_prefix)); |
| audit_log_format(ab, " pkey=0x%x subnet_prefix=%pI6c", |
| a->u.ibpkey->pkey, &sbn_pfx); |
| break; |
| } |
| case LSM_AUDIT_DATA_IBENDPORT: |
| audit_log_format(ab, " device=%s port_num=%u", |
| a->u.ibendport->dev_name, |
| a->u.ibendport->port); |
| break; |
| case LSM_AUDIT_DATA_LOCKDOWN: |
| audit_log_format(ab, " lockdown_reason=\"%s\"", |
| lockdown_reasons[a->u.reason]); |
| break; |
| case LSM_AUDIT_DATA_ANONINODE: |
| audit_log_format(ab, " anonclass=%s", a->u.anonclass); |
| break; |
| } /* switch (a->type) */ |
| } |
| |
| /** |
| * common_lsm_audit - generic LSM auditing function |
| * @a: auxiliary audit data |
| * @pre_audit: lsm-specific pre-audit callback |
| * @post_audit: lsm-specific post-audit callback |
| * |
| * setup the audit buffer for common security information |
| * uses callback to print LSM specific information |
| */ |
| void common_lsm_audit(struct common_audit_data *a, |
| void (*pre_audit)(struct audit_buffer *, void *), |
| void (*post_audit)(struct audit_buffer *, void *)) |
| { |
| struct audit_buffer *ab; |
| |
| if (a == NULL) |
| return; |
| /* we use GFP_ATOMIC so we won't sleep */ |
| ab = audit_log_start(audit_context(), GFP_ATOMIC | __GFP_NOWARN, |
| AUDIT_AVC); |
| |
| if (ab == NULL) |
| return; |
| |
| if (pre_audit) |
| pre_audit(ab, a); |
| |
| dump_common_audit_data(ab, a); |
| |
| if (post_audit) |
| post_audit(ab, a); |
| |
| audit_log_end(ab); |
| } |