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-rw-r--r--security/selinux/hooks.c200
1 files changed, 139 insertions, 61 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index d0cfaa9f19d0..f8110cfd80ff 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -242,6 +242,72 @@ static int inode_alloc_security(struct inode *inode)
return 0;
}
+static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
+
+/*
+ * Try reloading inode security labels that have been marked as invalid. The
+ * @may_sleep parameter indicates when sleeping and thus reloading labels is
+ * allowed; when set to false, returns ERR_PTR(-ECHILD) when the label is
+ * invalid. The @opt_dentry parameter should be set to a dentry of the inode;
+ * when no dentry is available, set it to NULL instead.
+ */
+static int __inode_security_revalidate(struct inode *inode,
+ struct dentry *opt_dentry,
+ bool may_sleep)
+{
+ struct inode_security_struct *isec = inode->i_security;
+
+ might_sleep_if(may_sleep);
+
+ if (isec->initialized == LABEL_INVALID) {
+ if (!may_sleep)
+ return -ECHILD;
+
+ /*
+ * Try reloading the inode security label. This will fail if
+ * @opt_dentry is NULL and no dentry for this inode can be
+ * found; in that case, continue using the old label.
+ */
+ inode_doinit_with_dentry(inode, opt_dentry);
+ }
+ return 0;
+}
+
+static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
+{
+ return inode->i_security;
+}
+
+static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
+{
+ int error;
+
+ error = __inode_security_revalidate(inode, NULL, !rcu);
+ if (error)
+ return ERR_PTR(error);
+ return inode->i_security;
+}
+
+/*
+ * Get the security label of an inode.
+ */
+static struct inode_security_struct *inode_security(struct inode *inode)
+{
+ __inode_security_revalidate(inode, NULL, true);
+ return inode->i_security;
+}
+
+/*
+ * Get the security label of a dentry's backing inode.
+ */
+static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
+{
+ struct inode *inode = d_backing_inode(dentry);
+
+ __inode_security_revalidate(inode, dentry, true);
+ return inode->i_security;
+}
+
static void inode_free_rcu(struct rcu_head *head)
{
struct inode_security_struct *isec;
@@ -345,8 +411,6 @@ static const char *labeling_behaviors[7] = {
"uses native labeling",
};
-static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
-
static inline int inode_doinit(struct inode *inode)
{
return inode_doinit_with_dentry(inode, NULL);
@@ -565,8 +629,8 @@ static int selinux_get_mnt_opts(const struct super_block *sb,
opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
}
if (sbsec->flags & ROOTCONTEXT_MNT) {
- struct inode *root = d_backing_inode(sbsec->sb->s_root);
- struct inode_security_struct *isec = root->i_security;
+ struct dentry *root = sbsec->sb->s_root;
+ struct inode_security_struct *isec = backing_inode_security(root);
rc = security_sid_to_context(isec->sid, &context, &len);
if (rc)
@@ -621,8 +685,8 @@ static int selinux_set_mnt_opts(struct super_block *sb,
int rc = 0, i;
struct superblock_security_struct *sbsec = sb->s_security;
const char *name = sb->s_type->name;
- struct inode *inode = d_backing_inode(sbsec->sb->s_root);
- struct inode_security_struct *root_isec = inode->i_security;
+ struct dentry *root = sbsec->sb->s_root;
+ struct inode_security_struct *root_isec = backing_inode_security(root);
u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
u32 defcontext_sid = 0;
char **mount_options = opts->mnt_opts;
@@ -802,7 +866,7 @@ static int selinux_set_mnt_opts(struct super_block *sb,
goto out;
root_isec->sid = rootcontext_sid;
- root_isec->initialized = 1;
+ root_isec->initialized = LABEL_INITIALIZED;
}
if (defcontext_sid) {
@@ -852,8 +916,8 @@ static int selinux_cmp_sb_context(const struct super_block *oldsb,
if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
goto mismatch;
if (oldflags & ROOTCONTEXT_MNT) {
- struct inode_security_struct *oldroot = d_backing_inode(oldsb->s_root)->i_security;
- struct inode_security_struct *newroot = d_backing_inode(newsb->s_root)->i_security;
+ struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
+ struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
if (oldroot->sid != newroot->sid)
goto mismatch;
}
@@ -903,17 +967,14 @@ static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
if (!set_fscontext)
newsbsec->sid = sid;
if (!set_rootcontext) {
- struct inode *newinode = d_backing_inode(newsb->s_root);
- struct inode_security_struct *newisec = newinode->i_security;
+ struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
newisec->sid = sid;
}
newsbsec->mntpoint_sid = sid;
}
if (set_rootcontext) {
- const struct inode *oldinode = d_backing_inode(oldsb->s_root);
- const struct inode_security_struct *oldisec = oldinode->i_security;
- struct inode *newinode = d_backing_inode(newsb->s_root);
- struct inode_security_struct *newisec = newinode->i_security;
+ const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
+ struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
newisec->sid = oldisec->sid;
}
@@ -1293,11 +1354,11 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
unsigned len = 0;
int rc = 0;
- if (isec->initialized)
+ if (isec->initialized == LABEL_INITIALIZED)
goto out;
mutex_lock(&isec->lock);
- if (isec->initialized)
+ if (isec->initialized == LABEL_INITIALIZED)
goto out_unlock;
sbsec = inode->i_sb->s_security;
@@ -1469,7 +1530,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
break;
}
- isec->initialized = 1;
+ isec->initialized = LABEL_INITIALIZED;
out_unlock:
mutex_unlock(&isec->lock);
@@ -1640,6 +1701,7 @@ static inline int dentry_has_perm(const struct cred *cred,
ad.type = LSM_AUDIT_DATA_DENTRY;
ad.u.dentry = dentry;
+ __inode_security_revalidate(inode, dentry, true);
return inode_has_perm(cred, inode, av, &ad);
}
@@ -1655,6 +1717,7 @@ static inline int path_has_perm(const struct cred *cred,
ad.type = LSM_AUDIT_DATA_PATH;
ad.u.path = *path;
+ __inode_security_revalidate(inode, path->dentry, true);
return inode_has_perm(cred, inode, av, &ad);
}
@@ -1712,13 +1775,13 @@ out:
/*
* Determine the label for an inode that might be unioned.
*/
-static int selinux_determine_inode_label(const struct inode *dir,
+static int selinux_determine_inode_label(struct inode *dir,
const struct qstr *name,
u16 tclass,
u32 *_new_isid)
{
const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
- const struct inode_security_struct *dsec = dir->i_security;
+ const struct inode_security_struct *dsec = inode_security(dir);
const struct task_security_struct *tsec = current_security();
if ((sbsec->flags & SE_SBINITIALIZED) &&
@@ -1747,7 +1810,7 @@ static int may_create(struct inode *dir,
struct common_audit_data ad;
int rc;
- dsec = dir->i_security;
+ dsec = inode_security(dir);
sbsec = dir->i_sb->s_security;
sid = tsec->sid;
@@ -1800,8 +1863,8 @@ static int may_link(struct inode *dir,
u32 av;
int rc;
- dsec = dir->i_security;
- isec = d_backing_inode(dentry)->i_security;
+ dsec = inode_security(dir);
+ isec = backing_inode_security(dentry);
ad.type = LSM_AUDIT_DATA_DENTRY;
ad.u.dentry = dentry;
@@ -1844,10 +1907,10 @@ static inline int may_rename(struct inode *old_dir,
int old_is_dir, new_is_dir;
int rc;
- old_dsec = old_dir->i_security;
- old_isec = d_backing_inode(old_dentry)->i_security;
+ old_dsec = inode_security(old_dir);
+ old_isec = backing_inode_security(old_dentry);
old_is_dir = d_is_dir(old_dentry);
- new_dsec = new_dir->i_security;
+ new_dsec = inode_security(new_dir);
ad.type = LSM_AUDIT_DATA_DENTRY;
@@ -1875,7 +1938,7 @@ static inline int may_rename(struct inode *old_dir,
if (rc)
return rc;
if (d_is_positive(new_dentry)) {
- new_isec = d_backing_inode(new_dentry)->i_security;
+ new_isec = backing_inode_security(new_dentry);
new_is_dir = d_is_dir(new_dentry);
rc = avc_has_perm(sid, new_isec->sid,
new_isec->sclass,
@@ -2011,8 +2074,8 @@ static int selinux_binder_transfer_file(struct task_struct *from,
{
u32 sid = task_sid(to);
struct file_security_struct *fsec = file->f_security;
- struct inode *inode = d_backing_inode(file->f_path.dentry);
- struct inode_security_struct *isec = inode->i_security;
+ struct dentry *dentry = file->f_path.dentry;
+ struct inode_security_struct *isec = backing_inode_security(dentry);
struct common_audit_data ad;
int rc;
@@ -2028,7 +2091,7 @@ static int selinux_binder_transfer_file(struct task_struct *from,
return rc;
}
- if (unlikely(IS_PRIVATE(inode)))
+ if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
@@ -2217,7 +2280,7 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
old_tsec = current_security();
new_tsec = bprm->cred->security;
- isec = inode->i_security;
+ isec = inode_security(inode);
/* Default to the current task SID. */
new_tsec->sid = old_tsec->sid;
@@ -2639,7 +2702,7 @@ static int selinux_sb_remount(struct super_block *sb, void *data)
break;
case ROOTCONTEXT_MNT: {
struct inode_security_struct *root_isec;
- root_isec = d_backing_inode(sb->s_root)->i_security;
+ root_isec = backing_inode_security(sb->s_root);
if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
goto out_bad_option;
@@ -2753,13 +2816,11 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
void **value, size_t *len)
{
const struct task_security_struct *tsec = current_security();
- struct inode_security_struct *dsec;
struct superblock_security_struct *sbsec;
u32 sid, newsid, clen;
int rc;
char *context;
- dsec = dir->i_security;
sbsec = dir->i_sb->s_security;
sid = tsec->sid;
@@ -2777,7 +2838,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
struct inode_security_struct *isec = inode->i_security;
isec->sclass = inode_mode_to_security_class(inode->i_mode);
isec->sid = newsid;
- isec->initialized = 1;
+ isec->initialized = LABEL_INITIALIZED;
}
if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT))
@@ -2858,7 +2919,9 @@ static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
ad.type = LSM_AUDIT_DATA_DENTRY;
ad.u.dentry = dentry;
sid = cred_sid(cred);
- isec = inode->i_security;
+ isec = inode_security_rcu(inode, rcu);
+ if (IS_ERR(isec))
+ return PTR_ERR(isec);
return avc_has_perm_flags(sid, isec->sid, isec->sclass, FILE__READ, &ad,
rcu ? MAY_NOT_BLOCK : 0);
@@ -2910,7 +2973,9 @@ static int selinux_inode_permission(struct inode *inode, int mask)
perms = file_mask_to_av(inode->i_mode, mask);
sid = cred_sid(cred);
- isec = inode->i_security;
+ isec = inode_security_rcu(inode, flags & MAY_NOT_BLOCK);
+ if (IS_ERR(isec))
+ return PTR_ERR(isec);
rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd);
audited = avc_audit_required(perms, &avd, rc,
@@ -2980,7 +3045,7 @@ static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
struct inode *inode = d_backing_inode(dentry);
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = backing_inode_security(dentry);
struct superblock_security_struct *sbsec;
struct common_audit_data ad;
u32 newsid, sid = current_sid();
@@ -3057,7 +3122,7 @@ static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
int flags)
{
struct inode *inode = d_backing_inode(dentry);
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = backing_inode_security(dentry);
u32 newsid;
int rc;
@@ -3076,7 +3141,7 @@ static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
isec->sclass = inode_mode_to_security_class(inode->i_mode);
isec->sid = newsid;
- isec->initialized = 1;
+ isec->initialized = LABEL_INITIALIZED;
return;
}
@@ -3110,12 +3175,12 @@ static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
*
* Permission check is handled by selinux_inode_getxattr hook.
*/
-static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
+static int selinux_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc)
{
u32 size;
int error;
char *context = NULL;
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = inode_security(inode);
if (strcmp(name, XATTR_SELINUX_SUFFIX))
return -EOPNOTSUPP;
@@ -3154,7 +3219,7 @@ out_nofree:
static int selinux_inode_setsecurity(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = inode_security(inode);
u32 newsid;
int rc;
@@ -3170,7 +3235,7 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name,
isec->sclass = inode_mode_to_security_class(inode->i_mode);
isec->sid = newsid;
- isec->initialized = 1;
+ isec->initialized = LABEL_INITIALIZED;
return 0;
}
@@ -3182,9 +3247,9 @@ static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t
return len;
}
-static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
+static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
{
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = inode_security(inode);
*secid = isec->sid;
}
@@ -3207,13 +3272,14 @@ static int selinux_file_permission(struct file *file, int mask)
{
struct inode *inode = file_inode(file);
struct file_security_struct *fsec = file->f_security;
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec;
u32 sid = current_sid();
if (!mask)
/* No permission to check. Existence test. */
return 0;
+ isec = inode_security(inode);
if (sid == fsec->sid && fsec->isid == isec->sid &&
fsec->pseqno == avc_policy_seqno())
/* No change since file_open check. */
@@ -3242,7 +3308,7 @@ static int ioctl_has_perm(const struct cred *cred, struct file *file,
struct common_audit_data ad;
struct file_security_struct *fsec = file->f_security;
struct inode *inode = file_inode(file);
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = inode_security(inode);
struct lsm_ioctlop_audit ioctl;
u32 ssid = cred_sid(cred);
int rc;
@@ -3506,7 +3572,7 @@ static int selinux_file_open(struct file *file, const struct cred *cred)
struct inode_security_struct *isec;
fsec = file->f_security;
- isec = file_inode(file)->i_security;
+ isec = inode_security(file_inode(file));
/*
* Save inode label and policy sequence number
* at open-time so that selinux_file_permission
@@ -3624,7 +3690,7 @@ static int selinux_kernel_act_as(struct cred *new, u32 secid)
*/
static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
{
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = inode_security(inode);
struct task_security_struct *tsec = new->security;
u32 sid = current_sid();
int ret;
@@ -3748,7 +3814,7 @@ static void selinux_task_to_inode(struct task_struct *p,
u32 sid = task_sid(p);
isec->sid = sid;
- isec->initialized = 1;
+ isec->initialized = LABEL_INITIALIZED;
}
/* Returns error only if unable to parse addresses */
@@ -4065,7 +4131,7 @@ static int selinux_socket_post_create(struct socket *sock, int family,
int type, int protocol, int kern)
{
const struct task_security_struct *tsec = current_security();
- struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
+ struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
struct sk_security_struct *sksec;
int err = 0;
@@ -4079,7 +4145,7 @@ static int selinux_socket_post_create(struct socket *sock, int family,
return err;
}
- isec->initialized = 1;
+ isec->initialized = LABEL_INITIALIZED;
if (sock->sk) {
sksec = sock->sk->sk_security;
@@ -4265,12 +4331,12 @@ static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
if (err)
return err;
- newisec = SOCK_INODE(newsock)->i_security;
+ newisec = inode_security_novalidate(SOCK_INODE(newsock));
- isec = SOCK_INODE(sock)->i_security;
+ isec = inode_security_novalidate(SOCK_INODE(sock));
newisec->sclass = isec->sclass;
newisec->sid = isec->sid;
- newisec->initialized = 1;
+ newisec->initialized = LABEL_INITIALIZED;
return 0;
}
@@ -4605,7 +4671,8 @@ static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
static void selinux_sock_graft(struct sock *sk, struct socket *parent)
{
- struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
+ struct inode_security_struct *isec =
+ inode_security_novalidate(SOCK_INODE(parent));
struct sk_security_struct *sksec = sk->sk_security;
if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
@@ -4785,11 +4852,12 @@ static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
if (err) {
if (err == -EINVAL) {
- printk(KERN_WARNING
- "SELinux: unrecognized netlink message:"
- " protocol=%hu nlmsg_type=%hu sclass=%s\n",
+ pr_warn_ratelimited("SELinux: unrecognized netlink"
+ " message: protocol=%hu nlmsg_type=%hu sclass=%s"
+ " pig=%d comm=%s\n",
sk->sk_protocol, nlh->nlmsg_type,
- secclass_map[sksec->sclass - 1].name);
+ secclass_map[sksec->sclass - 1].name,
+ task_pid_nr(current), current->comm);
if (!selinux_enforcing || security_get_allow_unknown())
err = 0;
}
@@ -5762,6 +5830,15 @@ static void selinux_release_secctx(char *secdata, u32 seclen)
kfree(secdata);
}
+static void selinux_inode_invalidate_secctx(struct inode *inode)
+{
+ struct inode_security_struct *isec = inode->i_security;
+
+ mutex_lock(&isec->lock);
+ isec->initialized = LABEL_INVALID;
+ mutex_unlock(&isec->lock);
+}
+
/*
* called with inode->i_mutex locked
*/
@@ -5993,6 +6070,7 @@ static struct security_hook_list selinux_hooks[] = {
LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx),
LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid),
LSM_HOOK_INIT(release_secctx, selinux_release_secctx),
+ LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx),
LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx),
LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx),