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-rw-r--r--security/smack/smack.h5
-rw-r--r--security/smack/smack_lsm.c145
-rw-r--r--security/smack/smackfs.c134
3 files changed, 183 insertions, 101 deletions
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 364cc64fce71..d072fd32212d 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -241,7 +241,8 @@ u32 smack_to_secid(const char *);
extern int smack_cipso_direct;
extern int smack_cipso_mapped;
extern struct smack_known *smack_net_ambient;
-extern char *smack_onlycap;
+extern struct smack_known *smack_onlycap;
+extern struct smack_known *smack_syslog_label;
extern const char *smack_cipso_option;
extern struct smack_known smack_known_floor;
@@ -312,7 +313,7 @@ static inline int smack_privileged(int cap)
if (!capable(cap))
return 0;
- if (smack_onlycap == NULL || smack_onlycap == skp->smk_known)
+ if (smack_onlycap == NULL || smack_onlycap == skp)
return 1;
return 0;
}
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index b0be893ad44d..14f52be78c75 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -219,8 +219,6 @@ static int smack_ptrace_traceme(struct task_struct *ptp)
* smack_syslog - Smack approval on syslog
* @type: message type
*
- * Require that the task has the floor label
- *
* Returns 0 on success, error code otherwise.
*/
static int smack_syslog(int typefrom_file)
@@ -231,7 +229,7 @@ static int smack_syslog(int typefrom_file)
if (smack_privileged(CAP_MAC_OVERRIDE))
return 0;
- if (skp != &smack_known_floor)
+ if (smack_syslog_label != NULL && smack_syslog_label != skp)
rc = -EACCES;
return rc;
@@ -341,10 +339,12 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
struct inode *inode = root->d_inode;
struct superblock_smack *sp = sb->s_security;
struct inode_smack *isp;
+ struct smack_known *skp;
char *op;
char *commap;
char *nsp;
int transmute = 0;
+ int specified = 0;
if (sp->smk_initialized)
return 0;
@@ -359,34 +359,56 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
op += strlen(SMK_FSHAT);
nsp = smk_import(op, 0);
- if (nsp != NULL)
+ if (nsp != NULL) {
sp->smk_hat = nsp;
+ specified = 1;
+ }
} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
op += strlen(SMK_FSFLOOR);
nsp = smk_import(op, 0);
- if (nsp != NULL)
+ if (nsp != NULL) {
sp->smk_floor = nsp;
+ specified = 1;
+ }
} else if (strncmp(op, SMK_FSDEFAULT,
strlen(SMK_FSDEFAULT)) == 0) {
op += strlen(SMK_FSDEFAULT);
nsp = smk_import(op, 0);
- if (nsp != NULL)
+ if (nsp != NULL) {
sp->smk_default = nsp;
+ specified = 1;
+ }
} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
op += strlen(SMK_FSROOT);
nsp = smk_import(op, 0);
- if (nsp != NULL)
+ if (nsp != NULL) {
sp->smk_root = nsp;
+ specified = 1;
+ }
} else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) {
op += strlen(SMK_FSTRANS);
nsp = smk_import(op, 0);
if (nsp != NULL) {
sp->smk_root = nsp;
transmute = 1;
+ specified = 1;
}
}
}
+ if (!smack_privileged(CAP_MAC_ADMIN)) {
+ /*
+ * Unprivileged mounts don't get to specify Smack values.
+ */
+ if (specified)
+ return -EPERM;
+ /*
+ * Unprivileged mounts get root and default from the caller.
+ */
+ skp = smk_of_current();
+ sp->smk_root = skp->smk_known;
+ sp->smk_default = skp->smk_known;
+ }
/*
* Initialize the root inode.
*/
@@ -423,53 +445,6 @@ static int smack_sb_statfs(struct dentry *dentry)
return rc;
}
-/**
- * smack_sb_mount - Smack check for mounting
- * @dev_name: unused
- * @path: mount point
- * @type: unused
- * @flags: unused
- * @data: unused
- *
- * Returns 0 if current can write the floor of the filesystem
- * being mounted on, an error code otherwise.
- */
-static int smack_sb_mount(const char *dev_name, struct path *path,
- const char *type, unsigned long flags, void *data)
-{
- struct superblock_smack *sbp = path->dentry->d_sb->s_security;
- struct smk_audit_info ad;
-
- smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
- smk_ad_setfield_u_fs_path(&ad, *path);
-
- return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
-}
-
-/**
- * smack_sb_umount - Smack check for unmounting
- * @mnt: file system to unmount
- * @flags: unused
- *
- * Returns 0 if current can write the floor of the filesystem
- * being unmounted, an error code otherwise.
- */
-static int smack_sb_umount(struct vfsmount *mnt, int flags)
-{
- struct superblock_smack *sbp;
- struct smk_audit_info ad;
- struct path path;
-
- path.dentry = mnt->mnt_root;
- path.mnt = mnt;
-
- smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
- smk_ad_setfield_u_fs_path(&ad, path);
-
- sbp = path.dentry->d_sb->s_security;
- return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
-}
-
/*
* BPRM hooks
*/
@@ -837,31 +812,43 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
struct smk_audit_info ad;
+ struct smack_known *skp;
+ int check_priv = 0;
+ int check_import = 0;
+ int check_star = 0;
int rc = 0;
+ /*
+ * Check label validity here so import won't fail in post_setxattr
+ */
if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
- strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
- strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
- strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
- if (!smack_privileged(CAP_MAC_ADMIN))
- rc = -EPERM;
- /*
- * check label validity here so import wont fail on
- * post_setxattr
- */
- if (size == 0 || size >= SMK_LONGLABEL ||
- smk_import(value, size) == NULL)
- rc = -EINVAL;
+ strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
+ check_priv = 1;
+ check_import = 1;
+ } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
+ strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
+ check_priv = 1;
+ check_import = 1;
+ check_star = 1;
} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
- if (!smack_privileged(CAP_MAC_ADMIN))
- rc = -EPERM;
+ check_priv = 1;
if (size != TRANS_TRUE_SIZE ||
strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
rc = -EINVAL;
} else
rc = cap_inode_setxattr(dentry, name, value, size, flags);
+ if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
+ rc = -EPERM;
+
+ if (rc == 0 && check_import) {
+ skp = smk_import_entry(value, size);
+ if (skp == NULL || (check_star &&
+ (skp == &smack_known_star || skp == &smack_known_web)))
+ rc = -EINVAL;
+ }
+
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
@@ -1364,7 +1351,7 @@ static int smack_file_receive(struct file *file)
int may = 0;
struct smk_audit_info ad;
- smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
+ smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
/*
* This code relies on bitmasks.
@@ -2847,8 +2834,17 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
if (rc >= 0)
transflag = SMK_INODE_TRANSMUTE;
}
- isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
- isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
+ /*
+ * Don't let the exec or mmap label be "*" or "@".
+ */
+ skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
+ if (skp == &smack_known_star || skp == &smack_known_web)
+ skp = NULL;
+ isp->smk_task = skp;
+ skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
+ if (skp == &smack_known_star || skp == &smack_known_web)
+ skp = NULL;
+ isp->smk_mmap = skp;
dput(dp);
break;
@@ -3620,9 +3616,8 @@ static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
struct smack_known *skp;
char *rule = vrule;
- if (!rule) {
- audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
- "Smack: missing rule\n");
+ if (unlikely(!rule)) {
+ WARN_ONCE(1, "Smack: missing rule\n");
return -ENOENT;
}
@@ -3743,8 +3738,6 @@ struct security_operations smack_ops = {
.sb_copy_data = smack_sb_copy_data,
.sb_kern_mount = smack_sb_kern_mount,
.sb_statfs = smack_sb_statfs,
- .sb_mount = smack_sb_mount,
- .sb_umount = smack_sb_umount,
.bprm_set_creds = smack_bprm_set_creds,
.bprm_committing_creds = smack_bprm_committing_creds,
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 160aa08e3cd5..3198cfe1dcc6 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -52,6 +52,7 @@ enum smk_inos {
SMK_CIPSO2 = 17, /* load long label -> CIPSO mapping */
SMK_REVOKE_SUBJ = 18, /* set rules with subject label to '-' */
SMK_CHANGE_RULE = 19, /* change or add rules (long labels) */
+ SMK_SYSLOG = 20, /* change syslog label) */
};
/*
@@ -59,6 +60,7 @@ enum smk_inos {
*/
static DEFINE_MUTEX(smack_cipso_lock);
static DEFINE_MUTEX(smack_ambient_lock);
+static DEFINE_MUTEX(smack_syslog_lock);
static DEFINE_MUTEX(smk_netlbladdr_lock);
/*
@@ -90,7 +92,13 @@ int smack_cipso_mapped = SMACK_CIPSO_MAPPED_DEFAULT;
* everyone. It is expected that the hat (^) label
* will be used if any label is used.
*/
-char *smack_onlycap;
+struct smack_known *smack_onlycap;
+
+/*
+ * If this value is set restrict syslog use to the label specified.
+ * It can be reset via smackfs/syslog
+ */
+struct smack_known *smack_syslog_label;
/*
* Certain IP addresses may be designated as single label hosts.
@@ -301,7 +309,8 @@ static int smk_perm_from_str(const char *string)
* @import: if non-zero, import labels
* @len: label length limit
*
- * Returns 0 on success, -1 on failure
+ * Returns 0 on success, -EINVAL on failure and -ENOENT when either subject
+ * or object is missing.
*/
static int smk_fill_rule(const char *subject, const char *object,
const char *access1, const char *access2,
@@ -314,28 +323,28 @@ static int smk_fill_rule(const char *subject, const char *object,
if (import) {
rule->smk_subject = smk_import_entry(subject, len);
if (rule->smk_subject == NULL)
- return -1;
+ return -EINVAL;
rule->smk_object = smk_import(object, len);
if (rule->smk_object == NULL)
- return -1;
+ return -EINVAL;
} else {
cp = smk_parse_smack(subject, len);
if (cp == NULL)
- return -1;
+ return -EINVAL;
skp = smk_find_entry(cp);
kfree(cp);
if (skp == NULL)
- return -1;
+ return -ENOENT;
rule->smk_subject = skp;
cp = smk_parse_smack(object, len);
if (cp == NULL)
- return -1;
+ return -EINVAL;
skp = smk_find_entry(cp);
kfree(cp);
if (skp == NULL)
- return -1;
+ return -ENOENT;
rule->smk_object = skp->smk_known;
}
@@ -381,6 +390,7 @@ static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule,
{
ssize_t cnt = 0;
char *tok[4];
+ int rc;
int i;
/*
@@ -405,10 +415,8 @@ static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule,
while (i < 4)
tok[i++] = NULL;
- if (smk_fill_rule(tok[0], tok[1], tok[2], tok[3], rule, import, 0))
- return -1;
-
- return cnt;
+ rc = smk_fill_rule(tok[0], tok[1], tok[2], tok[3], rule, import, 0);
+ return rc == 0 ? cnt : rc;
}
#define SMK_FIXED24_FMT 0 /* Fixed 24byte label format */
@@ -1603,7 +1611,7 @@ static const struct file_operations smk_ambient_ops = {
};
/**
- * smk_read_onlycap - read() for /smack/onlycap
+ * smk_read_onlycap - read() for smackfs/onlycap
* @filp: file pointer, not actually used
* @buf: where to put the result
* @cn: maximum to send along
@@ -1622,7 +1630,7 @@ static ssize_t smk_read_onlycap(struct file *filp, char __user *buf,
return 0;
if (smack_onlycap != NULL)
- smack = smack_onlycap;
+ smack = smack_onlycap->smk_known;
asize = strlen(smack) + 1;
@@ -1633,7 +1641,7 @@ static ssize_t smk_read_onlycap(struct file *filp, char __user *buf,
}
/**
- * smk_write_onlycap - write() for /smack/onlycap
+ * smk_write_onlycap - write() for smackfs/onlycap
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
@@ -1656,7 +1664,7 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf,
* explicitly for clarity. The smk_access() implementation
* would use smk_access(smack_onlycap, MAY_WRITE)
*/
- if (smack_onlycap != NULL && smack_onlycap != skp->smk_known)
+ if (smack_onlycap != NULL && smack_onlycap != skp)
return -EPERM;
data = kzalloc(count, GFP_KERNEL);
@@ -1676,7 +1684,7 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf,
if (copy_from_user(data, buf, count) != 0)
rc = -EFAULT;
else
- smack_onlycap = smk_import(data, count);
+ smack_onlycap = smk_import_entry(data, count);
kfree(data);
return rc;
@@ -1856,11 +1864,12 @@ static ssize_t smk_user_access(struct file *file, const char __user *buf,
res = smk_parse_long_rule(data, &rule, 0, 3);
}
- if (res < 0)
+ if (res >= 0)
+ res = smk_access(rule.smk_subject, rule.smk_object,
+ rule.smk_access1, NULL);
+ else if (res != -ENOENT)
return -EINVAL;
- res = smk_access(rule.smk_subject, rule.smk_object,
- rule.smk_access1, NULL);
data[0] = res == 0 ? '1' : '0';
data[1] = '\0';
@@ -2143,7 +2152,7 @@ static ssize_t smk_write_change_rule(struct file *file, const char __user *buf,
/*
* Must have privilege.
*/
- if (!capable(CAP_MAC_ADMIN))
+ if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
return smk_write_rules_list(file, buf, count, ppos, NULL, NULL,
@@ -2158,12 +2167,89 @@ static const struct file_operations smk_change_rule_ops = {
};
/**
- * smk_fill_super - fill the /smackfs superblock
+ * smk_read_syslog - read() for smackfs/syslog
+ * @filp: file pointer, not actually used
+ * @buf: where to put the result
+ * @cn: maximum to send along
+ * @ppos: where to start
+ *
+ * Returns number of bytes read or error code, as appropriate
+ */
+static ssize_t smk_read_syslog(struct file *filp, char __user *buf,
+ size_t cn, loff_t *ppos)
+{
+ struct smack_known *skp;
+ ssize_t rc = -EINVAL;
+ int asize;
+
+ if (*ppos != 0)
+ return 0;
+
+ if (smack_syslog_label == NULL)
+ skp = &smack_known_star;
+ else
+ skp = smack_syslog_label;
+
+ asize = strlen(skp->smk_known) + 1;
+
+ if (cn >= asize)
+ rc = simple_read_from_buffer(buf, cn, ppos, skp->smk_known,
+ asize);
+
+ return rc;
+}
+
+/**
+ * smk_write_syslog - write() for smackfs/syslog
+ * @file: file pointer, not actually used
+ * @buf: where to get the data from
+ * @count: bytes sent
+ * @ppos: where to start
+ *
+ * Returns number of bytes written or error code, as appropriate
+ */
+static ssize_t smk_write_syslog(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char *data;
+ struct smack_known *skp;
+ int rc = count;
+
+ if (!smack_privileged(CAP_MAC_ADMIN))
+ return -EPERM;
+
+ data = kzalloc(count, GFP_KERNEL);
+ if (data == NULL)
+ return -ENOMEM;
+
+ if (copy_from_user(data, buf, count) != 0)
+ rc = -EFAULT;
+ else {
+ skp = smk_import_entry(data, count);
+ if (skp == NULL)
+ rc = -EINVAL;
+ else
+ smack_syslog_label = smk_import_entry(data, count);
+ }
+
+ kfree(data);
+ return rc;
+}
+
+static const struct file_operations smk_syslog_ops = {
+ .read = smk_read_syslog,
+ .write = smk_write_syslog,
+ .llseek = default_llseek,
+};
+
+
+/**
+ * smk_fill_super - fill the smackfs superblock
* @sb: the empty superblock
* @data: unused
* @silent: unused
*
- * Fill in the well known entries for /smack
+ * Fill in the well known entries for the smack filesystem
*
* Returns 0 on success, an error code on failure
*/
@@ -2208,6 +2294,8 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent)
S_IRUGO|S_IWUSR},
[SMK_CHANGE_RULE] = {
"change-rule", &smk_change_rule_ops, S_IRUGO|S_IWUSR},
+ [SMK_SYSLOG] = {
+ "syslog", &smk_syslog_ops, S_IRUGO|S_IWUSR},
/* last one */
{""}
};
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-20 12:40:40 +0300