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-rw-r--r--security/smack/smack_access.c27
-rw-r--r--security/smack/smack_lsm.c93
-rw-r--r--security/smack/smackfs.c116
3 files changed, 139 insertions, 97 deletions
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 0f410fc56e33..408e20be1ad7 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -425,7 +425,7 @@ void smk_insert_entry(struct smack_known *skp)
* @string: a text string that might be a Smack label
*
* Returns a pointer to the entry in the label list that
- * matches the passed string.
+ * matches the passed string or NULL if not found.
*/
struct smack_known *smk_find_entry(const char *string)
{
@@ -448,7 +448,7 @@ struct smack_known *smk_find_entry(const char *string)
* @string: a text string that might contain a Smack label
* @len: the maximum size, or zero if it is NULL terminated.
*
- * Returns a pointer to the clean label, or NULL
+ * Returns a pointer to the clean label or an error code.
*/
char *smk_parse_smack(const char *string, int len)
{
@@ -464,7 +464,7 @@ char *smk_parse_smack(const char *string, int len)
* including /smack/cipso and /smack/cipso2
*/
if (string[0] == '-')
- return NULL;
+ return ERR_PTR(-EINVAL);
for (i = 0; i < len; i++)
if (string[i] > '~' || string[i] <= ' ' || string[i] == '/' ||
@@ -472,11 +472,13 @@ char *smk_parse_smack(const char *string, int len)
break;
if (i == 0 || i >= SMK_LONGLABEL)
- return NULL;
+ return ERR_PTR(-EINVAL);
smack = kzalloc(i + 1, GFP_KERNEL);
- if (smack != NULL)
- strncpy(smack, string, i);
+ if (smack == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ strncpy(smack, string, i);
return smack;
}
@@ -523,7 +525,8 @@ int smk_netlbl_mls(int level, char *catset, struct netlbl_lsm_secattr *sap,
* @len: the maximum size, or zero if it is NULL terminated.
*
* Returns a pointer to the entry in the label list that
- * matches the passed string, adding it if necessary.
+ * matches the passed string, adding it if necessary,
+ * or an error code.
*/
struct smack_known *smk_import_entry(const char *string, int len)
{
@@ -533,8 +536,8 @@ struct smack_known *smk_import_entry(const char *string, int len)
int rc;
smack = smk_parse_smack(string, len);
- if (smack == NULL)
- return NULL;
+ if (IS_ERR(smack))
+ return ERR_CAST(smack);
mutex_lock(&smack_known_lock);
@@ -543,8 +546,10 @@ struct smack_known *smk_import_entry(const char *string, int len)
goto freeout;
skp = kzalloc(sizeof(*skp), GFP_KERNEL);
- if (skp == NULL)
+ if (skp == NULL) {
+ skp = ERR_PTR(-ENOMEM);
goto freeout;
+ }
skp->smk_known = smack;
skp->smk_secid = smack_next_secid++;
@@ -577,7 +582,7 @@ struct smack_known *smk_import_entry(const char *string, int len)
* smk_netlbl_mls failed.
*/
kfree(skp);
- skp = NULL;
+ skp = ERR_PTR(rc);
freeout:
kfree(smack);
unlockout:
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index f09b8c7cf1e7..a143328f75eb 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -245,8 +245,8 @@ static int smk_bu_credfile(const struct cred *cred, struct file *file,
* @ip: a pointer to the inode
* @dp: a pointer to the dentry
*
- * Returns a pointer to the master list entry for the Smack label
- * or NULL if there was no label to fetch.
+ * Returns a pointer to the master list entry for the Smack label,
+ * NULL if there was no label to fetch, or an error code.
*/
static struct smack_known *smk_fetch(const char *name, struct inode *ip,
struct dentry *dp)
@@ -256,14 +256,18 @@ static struct smack_known *smk_fetch(const char *name, struct inode *ip,
struct smack_known *skp = NULL;
if (ip->i_op->getxattr == NULL)
- return NULL;
+ return ERR_PTR(-EOPNOTSUPP);
buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
if (buffer == NULL)
- return NULL;
+ return ERR_PTR(-ENOMEM);
rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL);
- if (rc > 0)
+ if (rc < 0)
+ skp = ERR_PTR(rc);
+ else if (rc == 0)
+ skp = NULL;
+ else
skp = smk_import_entry(buffer, rc);
kfree(buffer);
@@ -605,40 +609,44 @@ 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);
skp = smk_import_entry(op, 0);
- if (skp != NULL) {
- sp->smk_hat = skp;
- specified = 1;
- }
+ if (IS_ERR(skp))
+ return PTR_ERR(skp);
+ sp->smk_hat = skp;
+ specified = 1;
+
} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
op += strlen(SMK_FSFLOOR);
skp = smk_import_entry(op, 0);
- if (skp != NULL) {
- sp->smk_floor = skp;
- specified = 1;
- }
+ if (IS_ERR(skp))
+ return PTR_ERR(skp);
+ sp->smk_floor = skp;
+ specified = 1;
+
} else if (strncmp(op, SMK_FSDEFAULT,
strlen(SMK_FSDEFAULT)) == 0) {
op += strlen(SMK_FSDEFAULT);
skp = smk_import_entry(op, 0);
- if (skp != NULL) {
- sp->smk_default = skp;
- specified = 1;
- }
+ if (IS_ERR(skp))
+ return PTR_ERR(skp);
+ sp->smk_default = skp;
+ specified = 1;
+
} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
op += strlen(SMK_FSROOT);
skp = smk_import_entry(op, 0);
- if (skp != NULL) {
- sp->smk_root = skp;
- specified = 1;
- }
+ if (IS_ERR(skp))
+ return PTR_ERR(skp);
+ sp->smk_root = skp;
+ specified = 1;
+
} else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) {
op += strlen(SMK_FSTRANS);
skp = smk_import_entry(op, 0);
- if (skp != NULL) {
- sp->smk_root = skp;
- transmute = 1;
- specified = 1;
- }
+ if (IS_ERR(skp))
+ return PTR_ERR(skp);
+ sp->smk_root = skp;
+ transmute = 1;
+ specified = 1;
}
}
@@ -1118,7 +1126,9 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name,
if (rc == 0 && check_import) {
skp = size ? smk_import_entry(value, size) : NULL;
- if (skp == NULL || (check_star &&
+ if (IS_ERR(skp))
+ rc = PTR_ERR(skp);
+ else if (skp == NULL || (check_star &&
(skp == &smack_known_star || skp == &smack_known_web)))
rc = -EINVAL;
}
@@ -1158,19 +1168,19 @@ static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
if (strcmp(name, XATTR_NAME_SMACK) == 0) {
skp = smk_import_entry(value, size);
- if (skp != NULL)
+ if (!IS_ERR(skp))
isp->smk_inode = skp;
else
isp->smk_inode = &smack_known_invalid;
} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
skp = smk_import_entry(value, size);
- if (skp != NULL)
+ if (!IS_ERR(skp))
isp->smk_task = skp;
else
isp->smk_task = &smack_known_invalid;
} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
skp = smk_import_entry(value, size);
- if (skp != NULL)
+ if (!IS_ERR(skp))
isp->smk_mmap = skp;
else
isp->smk_mmap = &smack_known_invalid;
@@ -2403,8 +2413,8 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
return -EINVAL;
skp = smk_import_entry(value, size);
- if (skp == NULL)
- return -EINVAL;
+ if (IS_ERR(skp))
+ return PTR_ERR(skp);
if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
nsp->smk_inode = skp;
@@ -3177,7 +3187,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
*/
dp = dget(opt_dentry);
skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
- if (skp != NULL)
+ if (!IS_ERR_OR_NULL(skp))
final = skp;
/*
@@ -3214,11 +3224,14 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
* 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)
+ if (IS_ERR(skp) || 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)
+ if (IS_ERR(skp) || skp == &smack_known_star ||
+ skp == &smack_known_web)
skp = NULL;
isp->smk_mmap = skp;
@@ -3302,8 +3315,8 @@ static int smack_setprocattr(struct task_struct *p, char *name,
return -EINVAL;
skp = smk_import_entry(value, size);
- if (skp == NULL)
- return -EINVAL;
+ if (IS_ERR(skp))
+ return PTR_ERR(skp);
/*
* No process is ever allowed the web ("@") label.
@@ -4078,8 +4091,10 @@ static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
return -EINVAL;
skp = smk_import_entry(rulestr, 0);
- if (skp)
- *rule = skp->smk_known;
+ if (IS_ERR(skp))
+ return PTR_ERR(skp);
+
+ *rule = skp->smk_known;
return 0;
}
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 4aa12c8d3c63..3e4242617eea 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -338,8 +338,7 @@ static int smk_perm_from_str(const char *string)
* @import: if non-zero, import labels
* @len: label length limit
*
- * Returns 0 on success, -EINVAL on failure and -ENOENT when either subject
- * or object is missing.
+ * Returns 0 on success, appropriate error code on failure.
*/
static int smk_fill_rule(const char *subject, const char *object,
const char *access1, const char *access2,
@@ -351,16 +350,16 @@ 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 -EINVAL;
+ if (IS_ERR(rule->smk_subject))
+ return PTR_ERR(rule->smk_subject);
rule->smk_object = smk_import_entry(object, len);
- if (rule->smk_object == NULL)
- return -EINVAL;
+ if (IS_ERR(rule->smk_object))
+ return PTR_ERR(rule->smk_object);
} else {
cp = smk_parse_smack(subject, len);
- if (cp == NULL)
- return -EINVAL;
+ if (IS_ERR(cp))
+ return PTR_ERR(cp);
skp = smk_find_entry(cp);
kfree(cp);
if (skp == NULL)
@@ -368,8 +367,8 @@ static int smk_fill_rule(const char *subject, const char *object,
rule->smk_subject = skp;
cp = smk_parse_smack(object, len);
- if (cp == NULL)
- return -EINVAL;
+ if (IS_ERR(cp))
+ return PTR_ERR(cp);
skp = smk_find_entry(cp);
kfree(cp);
if (skp == NULL)
@@ -412,7 +411,7 @@ static int smk_parse_rule(const char *data, struct smack_parsed_rule *rule,
* @import: if non-zero, import labels
* @tokens: numer of substrings expected in data
*
- * Returns number of processed bytes on success, -1 on failure.
+ * Returns number of processed bytes on success, -ERRNO on failure.
*/
static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule,
int import, int tokens)
@@ -431,7 +430,7 @@ static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule,
if (data[cnt] == '\0')
/* Unexpected end of data */
- return -1;
+ return -EINVAL;
tok[i] = data + cnt;
@@ -529,14 +528,14 @@ static ssize_t smk_write_rules_list(struct file *file, const char __user *buf,
while (cnt < count) {
if (format == SMK_FIXED24_FMT) {
rc = smk_parse_rule(data, &rule, 1);
- if (rc != 0) {
- rc = -EINVAL;
+ if (rc < 0)
goto out;
- }
cnt = count;
} else {
rc = smk_parse_long_rule(data + cnt, &rule, 1, tokens);
- if (rc <= 0) {
+ if (rc < 0)
+ goto out;
+ if (rc == 0) {
rc = -EINVAL;
goto out;
}
@@ -915,8 +914,10 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
mutex_lock(&smack_cipso_lock);
skp = smk_import_entry(rule, 0);
- if (skp == NULL)
+ if (IS_ERR(skp)) {
+ rc = PTR_ERR(skp);
goto out;
+ }
if (format == SMK_FIXED24_FMT)
rule += SMK_LABELLEN;
@@ -1237,8 +1238,8 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
*/
if (smack[0] != '-') {
skp = smk_import_entry(smack, 0);
- if (skp == NULL) {
- rc = -EINVAL;
+ if (IS_ERR(skp)) {
+ rc = PTR_ERR(skp);
goto free_out;
}
} else {
@@ -1619,8 +1620,8 @@ static ssize_t smk_write_ambient(struct file *file, const char __user *buf,
}
skp = smk_import_entry(data, count);
- if (skp == NULL) {
- rc = -EINVAL;
+ if (IS_ERR(skp)) {
+ rc = PTR_ERR(skp);
goto out;
}
@@ -1704,21 +1705,31 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf,
if (data == NULL)
return -ENOMEM;
+ if (copy_from_user(data, buf, count) != 0) {
+ rc = -EFAULT;
+ goto freeout;
+ }
+
/*
- * Should the null string be passed in unset the onlycap value.
- * This seems like something to be careful with as usually
- * smk_import only expects to return NULL for errors. It
- * is usually the case that a nullstring or "\n" would be
- * bad to pass to smk_import but in fact this is useful here.
+ * Clear the smack_onlycap on invalid label errors. This means
+ * that we can pass a null string to unset the onlycap value.
*
- * smk_import will also reject a label beginning with '-',
+ * Importing will also reject a label beginning with '-',
* so "-usecapabilities" will also work.
+ *
+ * But do so only on invalid label, not on system errors.
*/
- if (copy_from_user(data, buf, count) != 0)
- rc = -EFAULT;
- else
- smack_onlycap = smk_import_entry(data, count);
+ skp = smk_import_entry(data, count);
+ if (PTR_ERR(skp) == -EINVAL)
+ skp = NULL;
+ else if (IS_ERR(skp)) {
+ rc = PTR_ERR(skp);
+ goto freeout;
+ }
+
+ smack_onlycap = skp;
+freeout:
kfree(data);
return rc;
}
@@ -1773,6 +1784,7 @@ static ssize_t smk_write_unconfined(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))
@@ -1782,21 +1794,31 @@ static ssize_t smk_write_unconfined(struct file *file, const char __user *buf,
if (data == NULL)
return -ENOMEM;
+ if (copy_from_user(data, buf, count) != 0) {
+ rc = -EFAULT;
+ goto freeout;
+ }
+
/*
- * Should the null string be passed in unset the unconfined value.
- * This seems like something to be careful with as usually
- * smk_import only expects to return NULL for errors. It
- * is usually the case that a nullstring or "\n" would be
- * bad to pass to smk_import but in fact this is useful here.
+ * Clear the smack_unconfined on invalid label errors. This means
+ * that we can pass a null string to unset the unconfined value.
*
- * smk_import will also reject a label beginning with '-',
+ * Importing will also reject a label beginning with '-',
* so "-confine" will also work.
+ *
+ * But do so only on invalid label, not on system errors.
*/
- if (copy_from_user(data, buf, count) != 0)
- rc = -EFAULT;
- else
- smack_unconfined = smk_import_entry(data, count);
+ skp = smk_import_entry(data, count);
+ if (PTR_ERR(skp) == -EINVAL)
+ skp = NULL;
+ else if (IS_ERR(skp)) {
+ rc = PTR_ERR(skp);
+ goto freeout;
+ }
+
+ smack_unconfined = skp;
+freeout:
kfree(data);
return rc;
}
@@ -1980,7 +2002,7 @@ static ssize_t smk_user_access(struct file *file, const char __user *buf,
res = smk_access(rule.smk_subject, rule.smk_object,
rule.smk_access1, NULL);
else if (res != -ENOENT)
- return -EINVAL;
+ return res;
/*
* smk_access() can return a value > 0 in the "bringup" case.
@@ -2209,8 +2231,8 @@ static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf,
}
cp = smk_parse_smack(data, count);
- if (cp == NULL) {
- rc = -EINVAL;
+ if (IS_ERR(cp)) {
+ rc = PTR_ERR(cp);
goto free_out;
}
@@ -2341,10 +2363,10 @@ static ssize_t smk_write_syslog(struct file *file, const char __user *buf,
rc = -EFAULT;
else {
skp = smk_import_entry(data, count);
- if (skp == NULL)
- rc = -EINVAL;
+ if (IS_ERR(skp))
+ rc = PTR_ERR(skp);
else
- smack_syslog_label = smk_import_entry(data, count);
+ smack_syslog_label = skp;
}
kfree(data);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.