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-rw-r--r--security/selinux/hooks.c182
1 files changed, 98 insertions, 84 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index d06e350fedee..10350534de6d 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1,10 +1,10 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * NSA Security-Enhanced Linux (SELinux) security module
+ * Security-Enhanced Linux (SELinux) security module
*
* This file contains the SELinux hook function implementations.
*
- * Authors: Stephen Smalley, <sds@tycho.nsa.gov>
+ * Authors: Stephen Smalley, <stephen.smalley.work@gmail.com>
* Chris Vance, <cvance@nai.com>
* Wayne Salamon, <wsalamon@nai.com>
* James Morris <jmorris@redhat.com>
@@ -104,6 +104,8 @@
#include "audit.h"
#include "avc_ss.h"
+#define SELINUX_INODE_INIT_XATTRS 1
+
struct selinux_state selinux_state;
/* SECMARK reference count */
@@ -224,6 +226,31 @@ static inline u32 cred_sid(const struct cred *cred)
return tsec->sid;
}
+static void __ad_net_init(struct common_audit_data *ad,
+ struct lsm_network_audit *net,
+ int ifindex, struct sock *sk, u16 family)
+{
+ ad->type = LSM_AUDIT_DATA_NET;
+ ad->u.net = net;
+ net->netif = ifindex;
+ net->sk = sk;
+ net->family = family;
+}
+
+static void ad_net_init_from_sk(struct common_audit_data *ad,
+ struct lsm_network_audit *net,
+ struct sock *sk)
+{
+ __ad_net_init(ad, net, 0, sk, 0);
+}
+
+static void ad_net_init_from_iif(struct common_audit_data *ad,
+ struct lsm_network_audit *net,
+ int ifindex, u16 family)
+{
+ __ad_net_init(ad, net, ifindex, NULL, family);
+}
+
/*
* get the objective security ID of a task
*/
@@ -1125,7 +1152,7 @@ static inline int default_protocol_dgram(int protocol)
static inline u16 socket_type_to_security_class(int family, int type, int protocol)
{
- int extsockclass = selinux_policycap_extsockclass();
+ bool extsockclass = selinux_policycap_extsockclass();
switch (family) {
case PF_UNIX:
@@ -1689,7 +1716,7 @@ static inline int file_path_has_perm(const struct cred *cred,
}
#ifdef CONFIG_BPF_SYSCALL
-static int bpf_fd_pass(struct file *file, u32 sid);
+static int bpf_fd_pass(const struct file *file, u32 sid);
#endif
/* Check whether a task can use an open file descriptor to
@@ -1950,7 +1977,7 @@ static inline u32 file_mask_to_av(int mode, int mask)
}
/* Convert a Linux file to an access vector. */
-static inline u32 file_to_av(struct file *file)
+static inline u32 file_to_av(const struct file *file)
{
u32 av = 0;
@@ -2025,7 +2052,7 @@ static int selinux_binder_transfer_binder(const struct cred *from,
static int selinux_binder_transfer_file(const struct cred *from,
const struct cred *to,
- struct file *file)
+ const struct file *file)
{
u32 sid = cred_sid(to);
struct file_security_struct *fsec = selinux_file(file);
@@ -2080,7 +2107,7 @@ static int selinux_ptrace_traceme(struct task_struct *parent)
SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
}
-static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
+static int selinux_capget(const struct task_struct *target, kernel_cap_t *effective,
kernel_cap_t *inheritable, kernel_cap_t *permitted)
{
return avc_has_perm(current_sid(), task_sid_obj(target),
@@ -2745,6 +2772,27 @@ static int selinux_umount(struct vfsmount *mnt, int flags)
FILESYSTEM__UNMOUNT, NULL);
}
+static int selinux_fs_context_submount(struct fs_context *fc,
+ struct super_block *reference)
+{
+ const struct superblock_security_struct *sbsec;
+ struct selinux_mnt_opts *opts;
+
+ opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+ if (!opts)
+ return -ENOMEM;
+
+ sbsec = selinux_superblock(reference);
+ if (sbsec->flags & FSCONTEXT_MNT)
+ opts->fscontext_sid = sbsec->sid;
+ if (sbsec->flags & CONTEXT_MNT)
+ opts->context_sid = sbsec->mntpoint_sid;
+ if (sbsec->flags & DEFCONTEXT_MNT)
+ opts->defcontext_sid = sbsec->def_sid;
+ fc->security = opts;
+ return 0;
+}
+
static int selinux_fs_context_dup(struct fs_context *fc,
struct fs_context *src_fc)
{
@@ -2847,11 +2895,11 @@ static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr,
- const char **name,
- void **value, size_t *len)
+ struct xattr *xattrs, int *xattr_count)
{
const struct task_security_struct *tsec = selinux_cred(current_cred());
struct superblock_security_struct *sbsec;
+ struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count);
u32 newsid, clen;
int rc;
char *context;
@@ -2878,16 +2926,14 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
!(sbsec->flags & SBLABEL_MNT))
return -EOPNOTSUPP;
- if (name)
- *name = XATTR_SELINUX_SUFFIX;
-
- if (value && len) {
+ if (xattr) {
rc = security_sid_to_context_force(newsid,
&context, &clen);
if (rc)
return rc;
- *value = context;
- *len = clen;
+ xattr->value = context;
+ xattr->value_len = clen;
+ xattr->name = XATTR_SELINUX_SUFFIX;
}
return 0;
@@ -2917,7 +2963,7 @@ static int selinux_inode_init_security_anon(struct inode *inode,
struct inode_security_struct *context_isec =
selinux_inode(context_inode);
if (context_isec->initialized != LABEL_INITIALIZED) {
- pr_err("SELinux: context_inode is not initialized");
+ pr_err("SELinux: context_inode is not initialized\n");
return -EACCES;
}
@@ -3762,13 +3808,10 @@ static int selinux_file_mprotect(struct vm_area_struct *vma,
if (default_noexec &&
(prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
int rc = 0;
- if (vma->vm_start >= vma->vm_mm->start_brk &&
- vma->vm_end <= vma->vm_mm->brk) {
+ if (vma_is_initial_heap(vma)) {
rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
PROCESS__EXECHEAP, NULL);
- } else if (!vma->vm_file &&
- ((vma->vm_start <= vma->vm_mm->start_stack &&
- vma->vm_end >= vma->vm_mm->start_stack) ||
+ } else if (!vma->vm_file && (vma_is_initial_stack(vma) ||
vma_is_stack_for_current(vma))) {
rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
PROCESS__EXECSTACK, NULL);
@@ -4499,14 +4542,12 @@ static int sock_has_perm(struct sock *sk, u32 perms)
{
struct sk_security_struct *sksec = sk->sk_security;
struct common_audit_data ad;
- struct lsm_network_audit net = {0,};
+ struct lsm_network_audit net;
if (sksec->sid == SECINITSID_KERNEL)
return 0;
- ad.type = LSM_AUDIT_DATA_NET;
- ad.u.net = &net;
- ad.u.net->sk = sk;
+ ad_net_init_from_sk(&ad, &net, sk);
return avc_has_perm(current_sid(), sksec->sid, sksec->sclass, perms,
&ad);
@@ -4899,12 +4940,10 @@ static int selinux_socket_unix_stream_connect(struct sock *sock,
struct sk_security_struct *sksec_other = other->sk_security;
struct sk_security_struct *sksec_new = newsk->sk_security;
struct common_audit_data ad;
- struct lsm_network_audit net = {0,};
+ struct lsm_network_audit net;
int err;
- ad.type = LSM_AUDIT_DATA_NET;
- ad.u.net = &net;
- ad.u.net->sk = other;
+ ad_net_init_from_sk(&ad, &net, other);
err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
sksec_other->sclass,
@@ -4931,11 +4970,9 @@ static int selinux_socket_unix_may_send(struct socket *sock,
struct sk_security_struct *ssec = sock->sk->sk_security;
struct sk_security_struct *osec = other->sk->sk_security;
struct common_audit_data ad;
- struct lsm_network_audit net = {0,};
+ struct lsm_network_audit net;
- ad.type = LSM_AUDIT_DATA_NET;
- ad.u.net = &net;
- ad.u.net->sk = other->sk;
+ ad_net_init_from_sk(&ad, &net, other->sk);
return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
&ad);
@@ -4971,13 +5008,10 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
struct sk_security_struct *sksec = sk->sk_security;
u32 sk_sid = sksec->sid;
struct common_audit_data ad;
- struct lsm_network_audit net = {0,};
+ struct lsm_network_audit net;
char *addrp;
- ad.type = LSM_AUDIT_DATA_NET;
- ad.u.net = &net;
- ad.u.net->netif = skb->skb_iif;
- ad.u.net->family = family;
+ ad_net_init_from_iif(&ad, &net, skb->skb_iif, family);
err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
if (err)
return err;
@@ -4999,15 +5033,13 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
- int err;
+ int err, peerlbl_active, secmark_active;
struct sk_security_struct *sksec = sk->sk_security;
u16 family = sk->sk_family;
u32 sk_sid = sksec->sid;
struct common_audit_data ad;
- struct lsm_network_audit net = {0,};
+ struct lsm_network_audit net;
char *addrp;
- u8 secmark_active;
- u8 peerlbl_active;
if (family != PF_INET && family != PF_INET6)
return 0;
@@ -5028,10 +5060,7 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
if (!secmark_active && !peerlbl_active)
return 0;
- ad.type = LSM_AUDIT_DATA_NET;
- ad.u.net = &net;
- ad.u.net->netif = skb->skb_iif;
- ad.u.net->family = family;
+ ad_net_init_from_iif(&ad, &net, skb->skb_iif, family);
err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
if (err)
return err;
@@ -5167,12 +5196,12 @@ static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
selinux_netlbl_sk_security_reset(newsksec);
}
-static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
+static void selinux_sk_getsecid(const struct sock *sk, u32 *secid)
{
if (!sk)
*secid = SECINITSID_ANY_SOCKET;
else {
- struct sk_security_struct *sksec = sk->sk_security;
+ const struct sk_security_struct *sksec = sk->sk_security;
*secid = sksec->sid;
}
@@ -5201,7 +5230,7 @@ static int selinux_sctp_process_new_assoc(struct sctp_association *asoc,
u16 family = sk->sk_family;
struct sk_security_struct *sksec = sk->sk_security;
struct common_audit_data ad;
- struct lsm_network_audit net = {0,};
+ struct lsm_network_audit net;
int err;
/* handle mapped IPv4 packets arriving via IPv6 sockets */
@@ -5237,9 +5266,7 @@ static int selinux_sctp_process_new_assoc(struct sctp_association *asoc,
/* Other association peer SIDs are checked to enforce
* consistency among the peer SIDs.
*/
- ad.type = LSM_AUDIT_DATA_NET;
- ad.u.net = &net;
- ad.u.net->sk = asoc->base.sk;
+ ad_net_init_from_sk(&ad, &net, asoc->base.sk);
err = avc_has_perm(sksec->peer_sid, asoc->peer_secid,
sksec->sclass, SCTP_SOCKET__ASSOCIATION,
&ad);
@@ -5470,11 +5497,11 @@ static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
static int selinux_secmark_relabel_packet(u32 sid)
{
- const struct task_security_struct *__tsec;
+ const struct task_security_struct *tsec;
u32 tsid;
- __tsec = selinux_cred(current_cred());
- tsid = __tsec->sid;
+ tsec = selinux_cred(current_cred());
+ tsid = tsec->sid;
return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO,
NULL);
@@ -5584,7 +5611,7 @@ static unsigned int selinux_ip_forward(void *priv, struct sk_buff *skb,
char *addrp;
u32 peer_sid;
struct common_audit_data ad;
- struct lsm_network_audit net = {0,};
+ struct lsm_network_audit net;
int secmark_active, peerlbl_active;
if (!selinux_policycap_netpeer())
@@ -5600,10 +5627,7 @@ static unsigned int selinux_ip_forward(void *priv, struct sk_buff *skb,
return NF_DROP;
ifindex = state->in->ifindex;
- ad.type = LSM_AUDIT_DATA_NET;
- ad.u.net = &net;
- ad.u.net->netif = ifindex;
- ad.u.net->family = family;
+ ad_net_init_from_iif(&ad, &net, ifindex, family);
if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
return NF_DROP;
@@ -5683,7 +5707,7 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
struct sock *sk;
struct sk_security_struct *sksec;
struct common_audit_data ad;
- struct lsm_network_audit net = {0,};
+ struct lsm_network_audit net;
u8 proto = 0;
sk = skb_to_full_sk(skb);
@@ -5691,10 +5715,7 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
return NF_ACCEPT;
sksec = sk->sk_security;
- ad.type = LSM_AUDIT_DATA_NET;
- ad.u.net = &net;
- ad.u.net->netif = state->out->ifindex;
- ad.u.net->family = state->pf;
+ ad_net_init_from_iif(&ad, &net, state->out->ifindex, state->pf);
if (selinux_parse_skb(skb, &ad, NULL, 0, &proto))
return NF_DROP;
@@ -5719,7 +5740,7 @@ static unsigned int selinux_ip_postroute(void *priv,
int ifindex;
struct sock *sk;
struct common_audit_data ad;
- struct lsm_network_audit net = {0,};
+ struct lsm_network_audit net;
char *addrp;
int secmark_active, peerlbl_active;
@@ -5816,10 +5837,7 @@ static unsigned int selinux_ip_postroute(void *priv,
}
ifindex = state->out->ifindex;
- ad.type = LSM_AUDIT_DATA_NET;
- ad.u.net = &net;
- ad.u.net->netif = ifindex;
- ad.u.net->family = family;
+ ad_net_init_from_iif(&ad, &net, ifindex, family);
if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
return NF_DROP;
@@ -5972,8 +5990,7 @@ static int selinux_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg)
static int selinux_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd)
{
- int err;
- int perms;
+ u32 perms;
switch (cmd) {
case IPC_INFO:
@@ -5996,8 +6013,7 @@ static int selinux_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd)
return 0;
}
- err = ipc_has_perm(msq, perms);
- return err;
+ return ipc_has_perm(msq, perms);
}
static int selinux_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg, int msqflg)
@@ -6102,8 +6118,7 @@ static int selinux_shm_associate(struct kern_ipc_perm *shp, int shmflg)
/* Note, at this point, shp is locked down */
static int selinux_shm_shmctl(struct kern_ipc_perm *shp, int cmd)
{
- int perms;
- int err;
+ u32 perms;
switch (cmd) {
case IPC_INFO:
@@ -6130,8 +6145,7 @@ static int selinux_shm_shmctl(struct kern_ipc_perm *shp, int cmd)
return 0;
}
- err = ipc_has_perm(shp, perms);
- return err;
+ return ipc_has_perm(shp, perms);
}
static int selinux_shm_shmat(struct kern_ipc_perm *shp,
@@ -6718,7 +6732,7 @@ static u32 bpf_map_fmode_to_av(fmode_t fmode)
* access the bpf object and that's why we have to add this additional check in
* selinux_file_receive and selinux_binder_transfer_files.
*/
-static int bpf_fd_pass(struct file *file, u32 sid)
+static int bpf_fd_pass(const struct file *file, u32 sid)
{
struct bpf_security_struct *bpfsec;
struct bpf_prog *prog;
@@ -6815,6 +6829,7 @@ struct lsm_blob_sizes selinux_blob_sizes __ro_after_init = {
.lbs_ipc = sizeof(struct ipc_security_struct),
.lbs_msg_msg = sizeof(struct msg_security_struct),
.lbs_superblock = sizeof(struct superblock_security_struct),
+ .lbs_xattr_count = SELINUX_INODE_INIT_XATTRS,
};
#ifdef CONFIG_PERF_EVENTS
@@ -6900,7 +6915,7 @@ static int selinux_uring_override_creds(const struct cred *new)
*/
static int selinux_uring_sqpoll(void)
{
- int sid = current_sid();
+ u32 sid = current_sid();
return avc_has_perm(sid, sid,
SECCLASS_IO_URING, IO_URING__SQPOLL, NULL);
@@ -6939,10 +6954,6 @@ static int selinux_uring_cmd(struct io_uring_cmd *ioucmd)
* hooks ("allocating" hooks).
*
* Please follow block comment delimiters in the list to keep this order.
- *
- * This ordering is needed for SELinux runtime disable to work at least somewhat
- * safely. Breaking the ordering rules above might lead to NULL pointer derefs
- * when disabling SELinux at runtime.
*/
static struct security_hook_list selinux_hooks[] __ro_after_init = {
LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
@@ -7182,6 +7193,7 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = {
/*
* PUT "CLONING" (ACCESSING + ALLOCATING) HOOKS HERE
*/
+ LSM_HOOK_INIT(fs_context_submount, selinux_fs_context_submount),
LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup),
LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param),
LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
@@ -7241,6 +7253,8 @@ static __init int selinux_init(void)
cred_init_security();
default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
+ if (!default_noexec)
+ pr_notice("SELinux: virtual memory is executable by default\n");
avc_init();