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linux/security/smack/smackfs.c
Jiawei Ye 2749749afa smackfs: Use rcu_assign_pointer() to ensure safe assignment in smk_set_cipso 
In the `smk_set_cipso` function, the `skp->smk_netlabel.attr.mls.cat`
field is directly assigned to a new value without using the appropriate
RCU pointer assignment functions. According to RCU usage rules, this is
illegal and can lead to unpredictable behavior, including data
inconsistencies and impossible-to-diagnose memory corruption issues.

This possible bug was identified using a static analysis tool developed
by myself, specifically designed to detect RCU-related issues.

To address this, the assignment is now done using rcu_assign_pointer(),
which ensures that the pointer assignment is done safely, with the
necessary memory barriers and synchronization. This change prevents
potential RCU dereference issues by ensuring that the `cat` field is
safely updated while still adhering to RCU's requirements.

Fixes: 0817534ff9 ("smackfs: Fix use-after-free in netlbl_catmap_walk()")
Signed-off-by: Jiawei Ye <jiawei.ye@foxmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2024-09-03 08:37:17 -07:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
*
* Authors:
* Casey Schaufler <casey@schaufler-ca.com>
* Ahmed S. Darwish <darwish.07@gmail.com>
*
* Special thanks to the authors of selinuxfs.
*
* Karl MacMillan <kmacmillan@tresys.com>
* James Morris <jmorris@redhat.com>
*/
#include <linux/kernel.h>
#include <linux/vmalloc.h>
#include <linux/security.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <net/net_namespace.h>
#include <net/cipso_ipv4.h>
#include <linux/seq_file.h>
#include <linux/ctype.h>
#include <linux/audit.h>
#include <linux/magic.h>
#include <linux/mount.h>
#include <linux/fs_context.h>
#include "smack.h"
#define BEBITS (sizeof(__be32) * 8)
/*
* smackfs pseudo filesystem.
*/
enum smk_inos {
SMK_ROOT_INO = 2,
SMK_LOAD = 3, /* load policy */
SMK_CIPSO = 4, /* load label -> CIPSO mapping */
SMK_DOI = 5, /* CIPSO DOI */
SMK_DIRECT = 6, /* CIPSO level indicating direct label */
SMK_AMBIENT = 7, /* internet ambient label */
SMK_NET4ADDR = 8, /* single label hosts */
SMK_ONLYCAP = 9, /* the only "capable" label */
SMK_LOGGING = 10, /* logging */
SMK_LOAD_SELF = 11, /* task specific rules */
SMK_ACCESSES = 12, /* access policy */
SMK_MAPPED = 13, /* CIPSO level indicating mapped label */
SMK_LOAD2 = 14, /* load policy with long labels */
SMK_LOAD_SELF2 = 15, /* load task specific rules with long labels */
SMK_ACCESS2 = 16, /* make an access check with long labels */
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) */
SMK_PTRACE = 21, /* set ptrace rule */
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
SMK_UNCONFINED = 22, /* define an unconfined label */
#endif
#if IS_ENABLED(CONFIG_IPV6)
SMK_NET6ADDR = 23, /* single label IPv6 hosts */
#endif /* CONFIG_IPV6 */
SMK_RELABEL_SELF = 24, /* relabel possible without CAP_MAC_ADMIN */
};
/*
* List locks
*/
static DEFINE_MUTEX(smack_cipso_lock);
static DEFINE_MUTEX(smack_ambient_lock);
static DEFINE_MUTEX(smk_net4addr_lock);
#if IS_ENABLED(CONFIG_IPV6)
static DEFINE_MUTEX(smk_net6addr_lock);
#endif /* CONFIG_IPV6 */
/*
* This is the "ambient" label for network traffic.
* If it isn't somehow marked, use this.
* It can be reset via smackfs/ambient
*/
struct smack_known *smack_net_ambient;
/*
* This is the level in a CIPSO header that indicates a
* smack label is contained directly in the category set.
* It can be reset via smackfs/direct
*/
int smack_cipso_direct = SMACK_CIPSO_DIRECT_DEFAULT;
/*
* This is the level in a CIPSO header that indicates a
* secid is contained directly in the category set.
* It can be reset via smackfs/mapped
*/
int smack_cipso_mapped = SMACK_CIPSO_MAPPED_DEFAULT;
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
/*
* Allow one label to be unconfined. This is for
* debugging and application bring-up purposes only.
* It is bad and wrong, but everyone seems to expect
* to have it.
*/
struct smack_known *smack_unconfined;
#endif
/*
* 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;
/*
* Ptrace current rule
* SMACK_PTRACE_DEFAULT regular smack ptrace rules (/proc based)
* SMACK_PTRACE_EXACT labels must match, but can be overriden with
* CAP_SYS_PTRACE
* SMACK_PTRACE_DRACONIAN labels must match, CAP_SYS_PTRACE has no effect
*/
int smack_ptrace_rule = SMACK_PTRACE_DEFAULT;
/*
* Certain IP addresses may be designated as single label hosts.
* Packets are sent there unlabeled, but only from tasks that
* can write to the specified label.
*/
LIST_HEAD(smk_net4addr_list);
#if IS_ENABLED(CONFIG_IPV6)
LIST_HEAD(smk_net6addr_list);
#endif /* CONFIG_IPV6 */
/*
* Rule lists are maintained for each label.
*/
struct smack_parsed_rule {
struct smack_known *smk_subject;
struct smack_known *smk_object;
int smk_access1;
int smk_access2;
};
static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT;
/*
* Values for parsing cipso rules
* SMK_DIGITLEN: Length of a digit field in a rule.
* SMK_CIPSOMIN: Minimum possible cipso rule length.
* SMK_CIPSOMAX: Maximum possible cipso rule length.
*/
#define SMK_DIGITLEN 4
#define SMK_CIPSOMIN (SMK_LABELLEN + 2 * SMK_DIGITLEN)
#define SMK_CIPSOMAX (SMK_CIPSOMIN + SMACK_CIPSO_MAXCATNUM * SMK_DIGITLEN)
/*
* Values for parsing MAC rules
* SMK_ACCESS: Maximum possible combination of access permissions
* SMK_ACCESSLEN: Maximum length for a rule access field
* SMK_LOADLEN: Smack rule length
*/
#define SMK_OACCESS "rwxa"
#define SMK_ACCESS "rwxatl"
#define SMK_OACCESSLEN (sizeof(SMK_OACCESS) - 1)
#define SMK_ACCESSLEN (sizeof(SMK_ACCESS) - 1)
#define SMK_OLOADLEN (SMK_LABELLEN + SMK_LABELLEN + SMK_OACCESSLEN)
#define SMK_LOADLEN (SMK_LABELLEN + SMK_LABELLEN + SMK_ACCESSLEN)
/*
* Stricly for CIPSO level manipulation.
* Set the category bit number in a smack label sized buffer.
*/
static inline void smack_catset_bit(unsigned int cat, char *catsetp)
{
if (cat == 0 || cat > (SMK_CIPSOLEN * 8))
return;
catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8);
}
/**
* smk_netlabel_audit_set - fill a netlbl_audit struct
* @nap: structure to fill
*/
static void smk_netlabel_audit_set(struct netlbl_audit *nap)
{
struct smack_known *skp = smk_of_current();
nap->loginuid = audit_get_loginuid(current);
nap->sessionid = audit_get_sessionid(current);
nap->secid = skp->smk_secid;
}
/*
* Value for parsing single label host rules
* "1.2.3.4 X"
*/
#define SMK_NETLBLADDRMIN 9
/**
* smk_set_access - add a rule to the rule list or replace an old rule
* @srp: the rule to add or replace
* @rule_list: the list of rules
* @rule_lock: the rule list lock
*
* Looks through the current subject/object/access list for
* the subject/object pair and replaces the access that was
* there. If the pair isn't found add it with the specified
* access.
*
* Returns 0 if nothing goes wrong or -ENOMEM if it fails
* during the allocation of the new pair to add.
*/
static int smk_set_access(struct smack_parsed_rule *srp,
struct list_head *rule_list,
struct mutex *rule_lock)
{
struct smack_rule *sp;
int found = 0;
int rc = 0;
mutex_lock(rule_lock);
/*
* Because the object label is less likely to match
* than the subject label check it first
*/
list_for_each_entry_rcu(sp, rule_list, list) {
if (sp->smk_object == srp->smk_object &&
sp->smk_subject == srp->smk_subject) {
found = 1;
sp->smk_access |= srp->smk_access1;
sp->smk_access &= ~srp->smk_access2;
break;
}
}
if (found == 0) {
sp = kmem_cache_zalloc(smack_rule_cache, GFP_KERNEL);
if (sp == NULL) {
rc = -ENOMEM;
goto out;
}
sp->smk_subject = srp->smk_subject;
sp->smk_object = srp->smk_object;
sp->smk_access = srp->smk_access1 & ~srp->smk_access2;
list_add_rcu(&sp->list, rule_list);
}
out:
mutex_unlock(rule_lock);
return rc;
}
/**
* smk_perm_from_str - parse smack accesses from a text string
* @string: a text string that contains a Smack accesses code
*
* Returns an integer with respective bits set for specified accesses.
*/
static int smk_perm_from_str(const char *string)
{
int perm = 0;
const char *cp;
for (cp = string; ; cp++)
switch (*cp) {
case '-':
break;
case 'r':
case 'R':
perm |= MAY_READ;
break;
case 'w':
case 'W':
perm |= MAY_WRITE;
break;
case 'x':
case 'X':
perm |= MAY_EXEC;
break;
case 'a':
case 'A':
perm |= MAY_APPEND;
break;
case 't':
case 'T':
perm |= MAY_TRANSMUTE;
break;
case 'l':
case 'L':
perm |= MAY_LOCK;
break;
case 'b':
case 'B':
perm |= MAY_BRINGUP;
break;
default:
return perm;
}
}
/**
* smk_fill_rule - Fill Smack rule from strings
* @subject: subject label string
* @object: object label string
* @access1: access string
* @access2: string with permissions to be removed
* @rule: Smack rule
* @import: if non-zero, import labels
* @len: label length limit
*
* 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,
struct smack_parsed_rule *rule, int import,
int len)
{
const char *cp;
struct smack_known *skp;
if (import) {
rule->smk_subject = smk_import_entry(subject, len);
if (IS_ERR(rule->smk_subject))
return PTR_ERR(rule->smk_subject);
rule->smk_object = smk_import_entry(object, len);
if (IS_ERR(rule->smk_object))
return PTR_ERR(rule->smk_object);
} else {
cp = smk_parse_smack(subject, len);
if (IS_ERR(cp))
return PTR_ERR(cp);
skp = smk_find_entry(cp);
kfree(cp);
if (skp == NULL)
return -ENOENT;
rule->smk_subject = skp;
cp = smk_parse_smack(object, len);
if (IS_ERR(cp))
return PTR_ERR(cp);
skp = smk_find_entry(cp);
kfree(cp);
if (skp == NULL)
return -ENOENT;
rule->smk_object = skp;
}
rule->smk_access1 = smk_perm_from_str(access1);
if (access2)
rule->smk_access2 = smk_perm_from_str(access2);
else
rule->smk_access2 = ~rule->smk_access1;
return 0;
}
/**
* smk_parse_rule - parse Smack rule from load string
* @data: string to be parsed whose size is SMK_LOADLEN
* @rule: Smack rule
* @import: if non-zero, import labels
*
* Returns 0 on success, -1 on errors.
*/
static int smk_parse_rule(const char *data, struct smack_parsed_rule *rule,
int import)
{
int rc;
rc = smk_fill_rule(data, data + SMK_LABELLEN,
data + SMK_LABELLEN + SMK_LABELLEN, NULL, rule,
import, SMK_LABELLEN);
return rc;
}
/**
* smk_parse_long_rule - parse Smack rule from rule string
* @data: string to be parsed, null terminated
* @rule: Will be filled with Smack parsed rule
* @import: if non-zero, import labels
* @tokens: number of substrings expected in data
*
* 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)
{
ssize_t cnt = 0;
char *tok[4];
int rc;
int i;
/*
* Parsing the rule in-place, filling all white-spaces with '\0'
*/
for (i = 0; i < tokens; ++i) {
while (isspace(data[cnt]))
data[cnt++] = '\0';
if (data[cnt] == '\0')
/* Unexpected end of data */
return -EINVAL;
tok[i] = data + cnt;
while (data[cnt] && !isspace(data[cnt]))
++cnt;
}
while (isspace(data[cnt]))
data[cnt++] = '\0';
while (i < 4)
tok[i++] = NULL;
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 */
#define SMK_LONG_FMT 1 /* Variable long label format */
#define SMK_CHANGE_FMT 2 /* Rule modification format */
/**
* smk_write_rules_list - write() for any /smack rule file
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start - must be 0
* @rule_list: the list of rules to write to
* @rule_lock: lock for the rule list
* @format: /smack/load or /smack/load2 or /smack/change-rule format.
*
* Get one smack access rule from above.
* The format for SMK_LONG_FMT is:
* "subject<whitespace>object<whitespace>access[<whitespace>...]"
* The format for SMK_FIXED24_FMT is exactly:
* "subject object rwxat"
* The format for SMK_CHANGE_FMT is:
* "subject<whitespace>object<whitespace>
* acc_enable<whitespace>acc_disable[<whitespace>...]"
*/
static ssize_t smk_write_rules_list(struct file *file, const char __user *buf,
size_t count, loff_t *ppos,
struct list_head *rule_list,
struct mutex *rule_lock, int format)
{
struct smack_parsed_rule rule;
char *data;
int rc;
int trunc = 0;
int tokens;
ssize_t cnt = 0;
/*
* No partial writes.
* Enough data must be present.
*/
if (*ppos != 0)
return -EINVAL;
if (format == SMK_FIXED24_FMT) {
/*
* Minor hack for backward compatibility
*/
if (count < SMK_OLOADLEN || count > SMK_LOADLEN)
return -EINVAL;
} else {
if (count >= PAGE_SIZE) {
count = PAGE_SIZE - 1;
trunc = 1;
}
}
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
/*
* In case of parsing only part of user buf,
* avoid having partial rule at the data buffer
*/
if (trunc) {
while (count > 0 && (data[count - 1] != '\n'))
--count;
if (count == 0) {
rc = -EINVAL;
goto out;
}
}
data[count] = '\0';
tokens = (format == SMK_CHANGE_FMT ? 4 : 3);
while (cnt < count) {
if (format == SMK_FIXED24_FMT) {
rc = smk_parse_rule(data, &rule, 1);
if (rc < 0)
goto out;
cnt = count;
} else {
rc = smk_parse_long_rule(data + cnt, &rule, 1, tokens);
if (rc < 0)
goto out;
if (rc == 0) {
rc = -EINVAL;
goto out;
}
cnt += rc;
}
if (rule_list == NULL)
rc = smk_set_access(&rule, &rule.smk_subject->smk_rules,
&rule.smk_subject->smk_rules_lock);
else
rc = smk_set_access(&rule, rule_list, rule_lock);
if (rc)
goto out;
}
rc = cnt;
out:
kfree(data);
return rc;
}
/*
* Core logic for smackfs seq list operations.
*/
static void *smk_seq_start(struct seq_file *s, loff_t *pos,
struct list_head *head)
{
struct list_head *list;
int i = *pos;
rcu_read_lock();
for (list = rcu_dereference(list_next_rcu(head));
list != head;
list = rcu_dereference(list_next_rcu(list))) {
if (i-- == 0)
return list;
}
return NULL;
}
static void *smk_seq_next(struct seq_file *s, void *v, loff_t *pos,
struct list_head *head)
{
struct list_head *list = v;
++*pos;
list = rcu_dereference(list_next_rcu(list));
return (list == head) ? NULL : list;
}
static void smk_seq_stop(struct seq_file *s, void *v)
{
rcu_read_unlock();
}
static void smk_rule_show(struct seq_file *s, struct smack_rule *srp, int max)
{
/*
* Don't show any rules with label names too long for
* interface file (/smack/load or /smack/load2)
* because you should expect to be able to write
* anything you read back.
*/
if (strlen(srp->smk_subject->smk_known) >= max ||
strlen(srp->smk_object->smk_known) >= max)
return;
if (srp->smk_access == 0)
return;
seq_printf(s, "%s %s",
srp->smk_subject->smk_known,
srp->smk_object->smk_known);
seq_putc(s, ' ');
if (srp->smk_access & MAY_READ)
seq_putc(s, 'r');
if (srp->smk_access & MAY_WRITE)
seq_putc(s, 'w');
if (srp->smk_access & MAY_EXEC)
seq_putc(s, 'x');
if (srp->smk_access & MAY_APPEND)
seq_putc(s, 'a');
if (srp->smk_access & MAY_TRANSMUTE)
seq_putc(s, 't');
if (srp->smk_access & MAY_LOCK)
seq_putc(s, 'l');
if (srp->smk_access & MAY_BRINGUP)
seq_putc(s, 'b');
seq_putc(s, '\n');
}
/*
* Seq_file read operations for /smack/load
*/
static void *load2_seq_start(struct seq_file *s, loff_t *pos)
{
return smk_seq_start(s, pos, &smack_known_list);
}
static void *load2_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
return smk_seq_next(s, v, pos, &smack_known_list);
}
static int load_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smack_rule *srp;
struct smack_known *skp =
list_entry_rcu(list, struct smack_known, list);
list_for_each_entry_rcu(srp, &skp->smk_rules, list)
smk_rule_show(s, srp, SMK_LABELLEN);
return 0;
}
static const struct seq_operations load_seq_ops = {
.start = load2_seq_start,
.next = load2_seq_next,
.show = load_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_load - open() for /smack/load
* @inode: inode structure representing file
* @file: "load" file pointer
*
* For reading, use load_seq_* seq_file reading operations.
*/
static int smk_open_load(struct inode *inode, struct file *file)
{
return seq_open(file, &load_seq_ops);
}
/**
* smk_write_load - write() for /smack/load
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start - must be 0
*
*/
static ssize_t smk_write_load(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
/*
* Must have privilege.
* No partial writes.
* Enough data must be present.
*/
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
return smk_write_rules_list(file, buf, count, ppos, NULL, NULL,
SMK_FIXED24_FMT);
}
static const struct file_operations smk_load_ops = {
.open = smk_open_load,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_load,
.release = seq_release,
};
/**
* smk_cipso_doi - initialize the CIPSO domain
*/
static void smk_cipso_doi(void)
{
int rc;
struct cipso_v4_doi *doip;
struct netlbl_audit nai;
smk_netlabel_audit_set(&nai);
rc = netlbl_cfg_map_del(NULL, PF_INET, NULL, NULL, &nai);
if (rc != 0)
printk(KERN_WARNING "%s:%d remove rc = %d\n",
__func__, __LINE__, rc);
doip = kmalloc(sizeof(struct cipso_v4_doi), GFP_KERNEL | __GFP_NOFAIL);
doip->map.std = NULL;
doip->doi = smk_cipso_doi_value;
doip->type = CIPSO_V4_MAP_PASS;
doip->tags[0] = CIPSO_V4_TAG_RBITMAP;
for (rc = 1; rc < CIPSO_V4_TAG_MAXCNT; rc++)
doip->tags[rc] = CIPSO_V4_TAG_INVALID;
rc = netlbl_cfg_cipsov4_add(doip, &nai);
if (rc != 0) {
printk(KERN_WARNING "%s:%d cipso add rc = %d\n",
__func__, __LINE__, rc);
kfree(doip);
return;
}
rc = netlbl_cfg_cipsov4_map_add(doip->doi, NULL, NULL, NULL, &nai);
if (rc != 0) {
printk(KERN_WARNING "%s:%d map add rc = %d\n",
__func__, __LINE__, rc);
netlbl_cfg_cipsov4_del(doip->doi, &nai);
return;
}
}
/**
* smk_unlbl_ambient - initialize the unlabeled domain
* @oldambient: previous domain string
*/
static void smk_unlbl_ambient(char *oldambient)
{
int rc;
struct netlbl_audit nai;
smk_netlabel_audit_set(&nai);
if (oldambient != NULL) {
rc = netlbl_cfg_map_del(oldambient, PF_INET, NULL, NULL, &nai);
if (rc != 0)
printk(KERN_WARNING "%s:%d remove rc = %d\n",
__func__, __LINE__, rc);
}
if (smack_net_ambient == NULL)
smack_net_ambient = &smack_known_floor;
rc = netlbl_cfg_unlbl_map_add(smack_net_ambient->smk_known, PF_INET,
NULL, NULL, &nai);
if (rc != 0)
printk(KERN_WARNING "%s:%d add rc = %d\n",
__func__, __LINE__, rc);
}
/*
* Seq_file read operations for /smack/cipso
*/
static void *cipso_seq_start(struct seq_file *s, loff_t *pos)
{
return smk_seq_start(s, pos, &smack_known_list);
}
static void *cipso_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
return smk_seq_next(s, v, pos, &smack_known_list);
}
/*
* Print cipso labels in format:
* label level[/cat[,cat]]
*/
static int cipso_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smack_known *skp =
list_entry_rcu(list, struct smack_known, list);
struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat;
char sep = '/';
int i;
/*
* Don't show a label that could not have been set using
* /smack/cipso. This is in support of the notion that
* anything read from /smack/cipso ought to be writeable
* to /smack/cipso.
*
* /smack/cipso2 should be used instead.
*/
if (strlen(skp->smk_known) >= SMK_LABELLEN)
return 0;
seq_printf(s, "%s %3d", skp->smk_known, skp->smk_netlabel.attr.mls.lvl);
for (i = netlbl_catmap_walk(cmp, 0); i >= 0;
i = netlbl_catmap_walk(cmp, i + 1)) {
seq_printf(s, "%c%d", sep, i);
sep = ',';
}
seq_putc(s, '\n');
return 0;
}
static const struct seq_operations cipso_seq_ops = {
.start = cipso_seq_start,
.next = cipso_seq_next,
.show = cipso_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_cipso - open() for /smack/cipso
* @inode: inode structure representing file
* @file: "cipso" file pointer
*
* Connect our cipso_seq_* operations with /smack/cipso
* file_operations
*/
static int smk_open_cipso(struct inode *inode, struct file *file)
{
return seq_open(file, &cipso_seq_ops);
}
/**
* smk_set_cipso - do the work for write() for cipso and cipso2
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start
* @format: /smack/cipso or /smack/cipso2
*
* Accepts only one cipso rule per write call.
* Returns number of bytes written or error code, as appropriate
*/
static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
size_t count, loff_t *ppos, int format)
{
struct netlbl_lsm_catmap *old_cat, *new_cat = NULL;
struct smack_known *skp;
struct netlbl_lsm_secattr ncats;
char mapcatset[SMK_CIPSOLEN];
int maplevel;
unsigned int cat;
int catlen;
ssize_t rc = -EINVAL;
char *data = NULL;
char *rule;
int ret;
int i;
/*
* Must have privilege.
* No partial writes.
* Enough data must be present.
*/
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (*ppos != 0)
return -EINVAL;
if (format == SMK_FIXED24_FMT &&
(count < SMK_CIPSOMIN || count > SMK_CIPSOMAX))
return -EINVAL;
if (count > PAGE_SIZE)
return -EINVAL;
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
rule = data;
/*
* Only allow one writer at a time. Writes should be
* quite rare and small in any case.
*/
mutex_lock(&smack_cipso_lock);
skp = smk_import_entry(rule, 0);
if (IS_ERR(skp)) {
rc = PTR_ERR(skp);
goto out;
}
if (format == SMK_FIXED24_FMT)
rule += SMK_LABELLEN;
else
rule += strlen(skp->smk_known) + 1;
if (rule > data + count) {
rc = -EOVERFLOW;
goto out;
}
ret = sscanf(rule, "%d", &maplevel);
if (ret != 1 || maplevel < 0 || maplevel > SMACK_CIPSO_MAXLEVEL)
goto out;
rule += SMK_DIGITLEN;
if (rule > data + count) {
rc = -EOVERFLOW;
goto out;
}
ret = sscanf(rule, "%d", &catlen);
if (ret != 1 || catlen < 0 || catlen > SMACK_CIPSO_MAXCATNUM)
goto out;
if (format == SMK_FIXED24_FMT &&
count != (SMK_CIPSOMIN + catlen * SMK_DIGITLEN))
goto out;
memset(mapcatset, 0, sizeof(mapcatset));
for (i = 0; i < catlen; i++) {
rule += SMK_DIGITLEN;
if (rule > data + count) {
rc = -EOVERFLOW;
goto out;
}
ret = sscanf(rule, "%u", &cat);
if (ret != 1 || cat > SMACK_CIPSO_MAXCATNUM)
goto out;
smack_catset_bit(cat, mapcatset);
}
ncats.flags = 0;
if (catlen == 0) {
ncats.attr.mls.cat = NULL;
ncats.attr.mls.lvl = maplevel;
new_cat = netlbl_catmap_alloc(GFP_ATOMIC);
if (new_cat)
new_cat->next = ncats.attr.mls.cat;
ncats.attr.mls.cat = new_cat;
skp->smk_netlabel.flags &= ~(1U << 3);
rc = 0;
} else {
rc = smk_netlbl_mls(maplevel, mapcatset, &ncats, SMK_CIPSOLEN);
}
if (rc >= 0) {
old_cat = skp->smk_netlabel.attr.mls.cat;
rcu_assign_pointer(skp->smk_netlabel.attr.mls.cat, ncats.attr.mls.cat);
skp->smk_netlabel.attr.mls.lvl = ncats.attr.mls.lvl;
synchronize_rcu();
netlbl_catmap_free(old_cat);
rc = count;
/*
* This mapping may have been cached, so clear the cache.
*/
netlbl_cache_invalidate();
}
out:
mutex_unlock(&smack_cipso_lock);
kfree(data);
return rc;
}
/**
* smk_write_cipso - write() for /smack/cipso
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start
*
* Accepts only one cipso rule per write call.
* Returns number of bytes written or error code, as appropriate
*/
static ssize_t smk_write_cipso(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
return smk_set_cipso(file, buf, count, ppos, SMK_FIXED24_FMT);
}
static const struct file_operations smk_cipso_ops = {
.open = smk_open_cipso,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_cipso,
.release = seq_release,
};
/*
* Seq_file read operations for /smack/cipso2
*/
/*
* Print cipso labels in format:
* label level[/cat[,cat]]
*/
static int cipso2_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smack_known *skp =
list_entry_rcu(list, struct smack_known, list);
struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat;
char sep = '/';
int i;
seq_printf(s, "%s %3d", skp->smk_known, skp->smk_netlabel.attr.mls.lvl);
for (i = netlbl_catmap_walk(cmp, 0); i >= 0;
i = netlbl_catmap_walk(cmp, i + 1)) {
seq_printf(s, "%c%d", sep, i);
sep = ',';
}
seq_putc(s, '\n');
return 0;
}
static const struct seq_operations cipso2_seq_ops = {
.start = cipso_seq_start,
.next = cipso_seq_next,
.show = cipso2_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_cipso2 - open() for /smack/cipso2
* @inode: inode structure representing file
* @file: "cipso2" file pointer
*
* Connect our cipso_seq_* operations with /smack/cipso2
* file_operations
*/
static int smk_open_cipso2(struct inode *inode, struct file *file)
{
return seq_open(file, &cipso2_seq_ops);
}
/**
* smk_write_cipso2 - write() for /smack/cipso2
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start
*
* Accepts only one cipso rule per write call.
* Returns number of bytes written or error code, as appropriate
*/
static ssize_t smk_write_cipso2(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
return smk_set_cipso(file, buf, count, ppos, SMK_LONG_FMT);
}
static const struct file_operations smk_cipso2_ops = {
.open = smk_open_cipso2,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_cipso2,
.release = seq_release,
};
/*
* Seq_file read operations for /smack/netlabel
*/
static void *net4addr_seq_start(struct seq_file *s, loff_t *pos)
{
return smk_seq_start(s, pos, &smk_net4addr_list);
}
static void *net4addr_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
return smk_seq_next(s, v, pos, &smk_net4addr_list);
}
/*
* Print host/label pairs
*/
static int net4addr_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smk_net4addr *skp =
list_entry_rcu(list, struct smk_net4addr, list);
char *kp = SMACK_CIPSO_OPTION;
if (skp->smk_label != NULL)
kp = skp->smk_label->smk_known;
seq_printf(s, "%pI4/%d %s\n", &skp->smk_host.s_addr,
skp->smk_masks, kp);
return 0;
}
static const struct seq_operations net4addr_seq_ops = {
.start = net4addr_seq_start,
.next = net4addr_seq_next,
.show = net4addr_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_net4addr - open() for /smack/netlabel
* @inode: inode structure representing file
* @file: "netlabel" file pointer
*
* Connect our net4addr_seq_* operations with /smack/netlabel
* file_operations
*/
static int smk_open_net4addr(struct inode *inode, struct file *file)
{
return seq_open(file, &net4addr_seq_ops);
}
/**
* smk_net4addr_insert
* @new : netlabel to insert
*
* This helper insert netlabel in the smack_net4addrs list
* sorted by netmask length (longest to smallest)
* locked by &smk_net4addr_lock in smk_write_net4addr
*
*/
static void smk_net4addr_insert(struct smk_net4addr *new)
{
struct smk_net4addr *m;
struct smk_net4addr *m_next;
if (list_empty(&smk_net4addr_list)) {
list_add_rcu(&new->list, &smk_net4addr_list);
return;
}
m = list_entry_rcu(smk_net4addr_list.next,
struct smk_net4addr, list);
/* the comparison '>' is a bit hacky, but works */
if (new->smk_masks > m->smk_masks) {
list_add_rcu(&new->list, &smk_net4addr_list);
return;
}
list_for_each_entry_rcu(m, &smk_net4addr_list, list) {
if (list_is_last(&m->list, &smk_net4addr_list)) {
list_add_rcu(&new->list, &m->list);
return;
}
m_next = list_entry_rcu(m->list.next,
struct smk_net4addr, list);
if (new->smk_masks > m_next->smk_masks) {
list_add_rcu(&new->list, &m->list);
return;
}
}
}
/**
* smk_write_net4addr - write() for /smack/netlabel
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start
*
* Accepts only one net4addr per write call.
* Returns number of bytes written or error code, as appropriate
*/
static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct smk_net4addr *snp;
struct sockaddr_in newname;
char *smack;
struct smack_known *skp = NULL;
char *data;
char *host = (char *)&newname.sin_addr.s_addr;
int rc;
struct netlbl_audit audit_info;
struct in_addr mask;
unsigned int m;
unsigned int masks;
int found;
u32 mask_bits = (1<<31);
__be32 nsa;
u32 temp_mask;
/*
* Must have privilege.
* No partial writes.
* Enough data must be present.
* "<addr/mask, as a.b.c.d/e><space><label>"
* "<addr, as a.b.c.d><space><label>"
*/
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (*ppos != 0)
return -EINVAL;
if (count < SMK_NETLBLADDRMIN || count > PAGE_SIZE - 1)
return -EINVAL;
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
smack = kzalloc(count + 1, GFP_KERNEL);
if (smack == NULL) {
rc = -ENOMEM;
goto free_data_out;
}
rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd/%u %s",
&host[0], &host[1], &host[2], &host[3], &masks, smack);
if (rc != 6) {
rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd %s",
&host[0], &host[1], &host[2], &host[3], smack);
if (rc != 5) {
rc = -EINVAL;
goto free_out;
}
masks = 32;
}
if (masks > BEBITS) {
rc = -EINVAL;
goto free_out;
}
/*
* If smack begins with '-', it is an option, don't import it
*/
if (smack[0] != '-') {
skp = smk_import_entry(smack, 0);
if (IS_ERR(skp)) {
rc = PTR_ERR(skp);
goto free_out;
}
} else {
/*
* Only the -CIPSO option is supported for IPv4
*/
if (strcmp(smack, SMACK_CIPSO_OPTION) != 0) {
rc = -EINVAL;
goto free_out;
}
}
for (m = masks, temp_mask = 0; m > 0; m--) {
temp_mask |= mask_bits;
mask_bits >>= 1;
}
mask.s_addr = cpu_to_be32(temp_mask);
newname.sin_addr.s_addr &= mask.s_addr;
/*
* Only allow one writer at a time. Writes should be
* quite rare and small in any case.
*/
mutex_lock(&smk_net4addr_lock);
nsa = newname.sin_addr.s_addr;
/* try to find if the prefix is already in the list */
found = 0;
list_for_each_entry_rcu(snp, &smk_net4addr_list, list) {
if (snp->smk_host.s_addr == nsa && snp->smk_masks == masks) {
found = 1;
break;
}
}
smk_netlabel_audit_set(&audit_info);
if (found == 0) {
snp = kzalloc(sizeof(*snp), GFP_KERNEL);
if (snp == NULL)
rc = -ENOMEM;
else {
rc = 0;
snp->smk_host.s_addr = newname.sin_addr.s_addr;
snp->smk_mask.s_addr = mask.s_addr;
snp->smk_label = skp;
snp->smk_masks = masks;
smk_net4addr_insert(snp);
}
} else {
/*
* Delete the unlabeled entry, only if the previous label
* wasn't the special CIPSO option
*/
if (snp->smk_label != NULL)
rc = netlbl_cfg_unlbl_static_del(&init_net, NULL,
&snp->smk_host, &snp->smk_mask,
PF_INET, &audit_info);
else
rc = 0;
snp->smk_label = skp;
}
/*
* Now tell netlabel about the single label nature of
* this host so that incoming packets get labeled.
* but only if we didn't get the special CIPSO option
*/
if (rc == 0 && skp != NULL)
rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
&snp->smk_host, &snp->smk_mask, PF_INET,
snp->smk_label->smk_secid, &audit_info);
if (rc == 0)
rc = count;
mutex_unlock(&smk_net4addr_lock);
free_out:
kfree(smack);
free_data_out:
kfree(data);
return rc;
}
static const struct file_operations smk_net4addr_ops = {
.open = smk_open_net4addr,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_net4addr,
.release = seq_release,
};
#if IS_ENABLED(CONFIG_IPV6)
/*
* Seq_file read operations for /smack/netlabel6
*/
static void *net6addr_seq_start(struct seq_file *s, loff_t *pos)
{
return smk_seq_start(s, pos, &smk_net6addr_list);
}
static void *net6addr_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
return smk_seq_next(s, v, pos, &smk_net6addr_list);
}
/*
* Print host/label pairs
*/
static int net6addr_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smk_net6addr *skp =
list_entry(list, struct smk_net6addr, list);
if (skp->smk_label != NULL)
seq_printf(s, "%pI6/%d %s\n", &skp->smk_host, skp->smk_masks,
skp->smk_label->smk_known);
return 0;
}
static const struct seq_operations net6addr_seq_ops = {
.start = net6addr_seq_start,
.next = net6addr_seq_next,
.show = net6addr_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_net6addr - open() for /smack/netlabel
* @inode: inode structure representing file
* @file: "netlabel" file pointer
*
* Connect our net6addr_seq_* operations with /smack/netlabel
* file_operations
*/
static int smk_open_net6addr(struct inode *inode, struct file *file)
{
return seq_open(file, &net6addr_seq_ops);
}
/**
* smk_net6addr_insert
* @new : entry to insert
*
* This inserts an entry in the smack_net6addrs list
* sorted by netmask length (longest to smallest)
* locked by &smk_net6addr_lock in smk_write_net6addr
*
*/
static void smk_net6addr_insert(struct smk_net6addr *new)
{
struct smk_net6addr *m_next;
struct smk_net6addr *m;
if (list_empty(&smk_net6addr_list)) {
list_add_rcu(&new->list, &smk_net6addr_list);
return;
}
m = list_entry_rcu(smk_net6addr_list.next,
struct smk_net6addr, list);
if (new->smk_masks > m->smk_masks) {
list_add_rcu(&new->list, &smk_net6addr_list);
return;
}
list_for_each_entry_rcu(m, &smk_net6addr_list, list) {
if (list_is_last(&m->list, &smk_net6addr_list)) {
list_add_rcu(&new->list, &m->list);
return;
}
m_next = list_entry_rcu(m->list.next,
struct smk_net6addr, list);
if (new->smk_masks > m_next->smk_masks) {
list_add_rcu(&new->list, &m->list);
return;
}
}
}
/**
* smk_write_net6addr - write() for /smack/netlabel
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start
*
* Accepts only one net6addr per write call.
* Returns number of bytes written or error code, as appropriate
*/
static ssize_t smk_write_net6addr(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct smk_net6addr *snp;
struct in6_addr newname;
struct in6_addr fullmask;
struct smack_known *skp = NULL;
char *smack;
char *data;
int rc = 0;
int found = 0;
int i;
unsigned int scanned[8];
unsigned int m;
unsigned int mask = 128;
/*
* Must have privilege.
* No partial writes.
* Enough data must be present.
* "<addr/mask, as a:b:c:d:e:f:g:h/e><space><label>"
* "<addr, as a:b:c:d:e:f:g:h><space><label>"
*/
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (*ppos != 0)
return -EINVAL;
if (count < SMK_NETLBLADDRMIN || count > PAGE_SIZE - 1)
return -EINVAL;
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
smack = kzalloc(count + 1, GFP_KERNEL);
if (smack == NULL) {
rc = -ENOMEM;
goto free_data_out;
}
i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x/%u %s",
&scanned[0], &scanned[1], &scanned[2], &scanned[3],
&scanned[4], &scanned[5], &scanned[6], &scanned[7],
&mask, smack);
if (i != 10) {
i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x %s",
&scanned[0], &scanned[1], &scanned[2],
&scanned[3], &scanned[4], &scanned[5],
&scanned[6], &scanned[7], smack);
if (i != 9) {
rc = -EINVAL;
goto free_out;
}
}
if (mask > 128) {
rc = -EINVAL;
goto free_out;
}
for (i = 0; i < 8; i++) {
if (scanned[i] > 0xffff) {
rc = -EINVAL;
goto free_out;
}
newname.s6_addr16[i] = htons(scanned[i]);
}
/*
* If smack begins with '-', it is an option, don't import it
*/
if (smack[0] != '-') {
skp = smk_import_entry(smack, 0);
if (IS_ERR(skp)) {
rc = PTR_ERR(skp);
goto free_out;
}
} else {
/*
* Only -DELETE is supported for IPv6
*/
if (strcmp(smack, SMACK_DELETE_OPTION) != 0) {
rc = -EINVAL;
goto free_out;
}
}
for (i = 0, m = mask; i < 8; i++) {
if (m >= 16) {
fullmask.s6_addr16[i] = 0xffff;
m -= 16;
} else if (m > 0) {
fullmask.s6_addr16[i] = (1 << m) - 1;
m = 0;
} else
fullmask.s6_addr16[i] = 0;
newname.s6_addr16[i] &= fullmask.s6_addr16[i];
}
/*
* Only allow one writer at a time. Writes should be
* quite rare and small in any case.
*/
mutex_lock(&smk_net6addr_lock);
/*
* Try to find the prefix in the list
*/
list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
if (mask != snp->smk_masks)
continue;
for (found = 1, i = 0; i < 8; i++) {
if (newname.s6_addr16[i] !=
snp->smk_host.s6_addr16[i]) {
found = 0;
break;
}
}
if (found == 1)
break;
}
if (found == 0) {
snp = kzalloc(sizeof(*snp), GFP_KERNEL);
if (snp == NULL)
rc = -ENOMEM;
else {
snp->smk_host = newname;
snp->smk_mask = fullmask;
snp->smk_masks = mask;
snp->smk_label = skp;
smk_net6addr_insert(snp);
}
} else {
snp->smk_label = skp;
}
if (rc == 0)
rc = count;
mutex_unlock(&smk_net6addr_lock);
free_out:
kfree(smack);
free_data_out:
kfree(data);
return rc;
}
static const struct file_operations smk_net6addr_ops = {
.open = smk_open_net6addr,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_net6addr,
.release = seq_release,
};
#endif /* CONFIG_IPV6 */
/**
* smk_read_doi - read() for /smack/doi
* @filp: file pointer, not actually used
* @buf: where to put the result
* @count: maximum to send along
* @ppos: where to start
*
* Returns number of bytes read or error code, as appropriate
*/
static ssize_t smk_read_doi(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char temp[80];
ssize_t rc;
if (*ppos != 0)
return 0;
sprintf(temp, "%d", smk_cipso_doi_value);
rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
return rc;
}
/**
* smk_write_doi - write() for /smack/doi
* @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_doi(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char temp[80];
int i;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (count >= sizeof(temp) || count == 0)
return -EINVAL;
if (copy_from_user(temp, buf, count) != 0)
return -EFAULT;
temp[count] = '\0';
if (sscanf(temp, "%d", &i) != 1)
return -EINVAL;
smk_cipso_doi_value = i;
smk_cipso_doi();
return count;
}
static const struct file_operations smk_doi_ops = {
.read = smk_read_doi,
.write = smk_write_doi,
.llseek = default_llseek,
};
/**
* smk_read_direct - read() for /smack/direct
* @filp: file pointer, not actually used
* @buf: where to put the result
* @count: maximum to send along
* @ppos: where to start
*
* Returns number of bytes read or error code, as appropriate
*/
static ssize_t smk_read_direct(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char temp[80];
ssize_t rc;
if (*ppos != 0)
return 0;
sprintf(temp, "%d", smack_cipso_direct);
rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
return rc;
}
/**
* smk_write_direct - write() for /smack/direct
* @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_direct(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct smack_known *skp;
char temp[80];
int i;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (count >= sizeof(temp) || count == 0)
return -EINVAL;
if (copy_from_user(temp, buf, count) != 0)
return -EFAULT;
temp[count] = '\0';
if (sscanf(temp, "%d", &i) != 1)
return -EINVAL;
/*
* Don't do anything if the value hasn't actually changed.
* If it is changing reset the level on entries that were
* set up to be direct when they were created.
*/
if (smack_cipso_direct != i) {
mutex_lock(&smack_known_lock);
list_for_each_entry_rcu(skp, &smack_known_list, list)
if (skp->smk_netlabel.attr.mls.lvl ==
smack_cipso_direct)
skp->smk_netlabel.attr.mls.lvl = i;
smack_cipso_direct = i;
mutex_unlock(&smack_known_lock);
}
return count;
}
static const struct file_operations smk_direct_ops = {
.read = smk_read_direct,
.write = smk_write_direct,
.llseek = default_llseek,
};
/**
* smk_read_mapped - read() for /smack/mapped
* @filp: file pointer, not actually used
* @buf: where to put the result
* @count: maximum to send along
* @ppos: where to start
*
* Returns number of bytes read or error code, as appropriate
*/
static ssize_t smk_read_mapped(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char temp[80];
ssize_t rc;
if (*ppos != 0)
return 0;
sprintf(temp, "%d", smack_cipso_mapped);
rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
return rc;
}
/**
* smk_write_mapped - write() for /smack/mapped
* @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_mapped(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct smack_known *skp;
char temp[80];
int i;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (count >= sizeof(temp) || count == 0)
return -EINVAL;
if (copy_from_user(temp, buf, count) != 0)
return -EFAULT;
temp[count] = '\0';
if (sscanf(temp, "%d", &i) != 1)
return -EINVAL;
/*
* Don't do anything if the value hasn't actually changed.
* If it is changing reset the level on entries that were
* set up to be mapped when they were created.
*/
if (smack_cipso_mapped != i) {
mutex_lock(&smack_known_lock);
list_for_each_entry_rcu(skp, &smack_known_list, list)
if (skp->smk_netlabel.attr.mls.lvl ==
smack_cipso_mapped)
skp->smk_netlabel.attr.mls.lvl = i;
smack_cipso_mapped = i;
mutex_unlock(&smack_known_lock);
}
return count;
}
static const struct file_operations smk_mapped_ops = {
.read = smk_read_mapped,
.write = smk_write_mapped,
.llseek = default_llseek,
};
/**
* smk_read_ambient - read() for /smack/ambient
* @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_ambient(struct file *filp, char __user *buf,
size_t cn, loff_t *ppos)
{
ssize_t rc;
int asize;
if (*ppos != 0)
return 0;
/*
* Being careful to avoid a problem in the case where
* smack_net_ambient gets changed in midstream.
*/
mutex_lock(&smack_ambient_lock);
asize = strlen(smack_net_ambient->smk_known) + 1;
if (cn >= asize)
rc = simple_read_from_buffer(buf, cn, ppos,
smack_net_ambient->smk_known,
asize);
else
rc = -EINVAL;
mutex_unlock(&smack_ambient_lock);
return rc;
}
/**
* smk_write_ambient - write() for /smack/ambient
* @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_ambient(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct smack_known *skp;
char *oldambient;
char *data;
int rc = count;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
/* Enough data must be present */
if (count == 0 || count > PAGE_SIZE)
return -EINVAL;
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
skp = smk_import_entry(data, count);
if (IS_ERR(skp)) {
rc = PTR_ERR(skp);
goto out;
}
mutex_lock(&smack_ambient_lock);
oldambient = smack_net_ambient->smk_known;
smack_net_ambient = skp;
smk_unlbl_ambient(oldambient);
mutex_unlock(&smack_ambient_lock);
out:
kfree(data);
return rc;
}
static const struct file_operations smk_ambient_ops = {
.read = smk_read_ambient,
.write = smk_write_ambient,
.llseek = default_llseek,
};
/*
* Seq_file operations for /smack/onlycap
*/
static void *onlycap_seq_start(struct seq_file *s, loff_t *pos)
{
return smk_seq_start(s, pos, &smack_onlycap_list);
}
static void *onlycap_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
return smk_seq_next(s, v, pos, &smack_onlycap_list);
}
static int onlycap_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smack_known_list_elem *sklep =
list_entry_rcu(list, struct smack_known_list_elem, list);
seq_puts(s, sklep->smk_label->smk_known);
seq_putc(s, ' ');
return 0;
}
static const struct seq_operations onlycap_seq_ops = {
.start = onlycap_seq_start,
.next = onlycap_seq_next,
.show = onlycap_seq_show,
.stop = smk_seq_stop,
};
static int smk_open_onlycap(struct inode *inode, struct file *file)
{
return seq_open(file, &onlycap_seq_ops);
}
/**
* smk_list_swap_rcu - swap public list with a private one in RCU-safe way
* The caller must hold appropriate mutex to prevent concurrent modifications
* to the public list.
* Private list is assumed to be not accessible to other threads yet.
*
* @public: public list
* @private: private list
*/
static void smk_list_swap_rcu(struct list_head *public,
struct list_head *private)
{
struct list_head *first, *last;
if (list_empty(public)) {
list_splice_init_rcu(private, public, synchronize_rcu);
} else {
/* Remember public list before replacing it */
first = public->next;
last = public->prev;
/* Publish private list in place of public in RCU-safe way */
private->prev->next = public;
private->next->prev = public;
rcu_assign_pointer(public->next, private->next);
public->prev = private->prev;
synchronize_rcu();
/* When all readers are done with the old public list,
* attach it in place of private */
private->next = first;
private->prev = last;
first->prev = private;
last->next = private;
}
}
/**
* smk_parse_label_list - parse list of Smack labels, separated by spaces
*
* @data: the string to parse
* @list: destination list
*
* Returns zero on success or error code, as appropriate
*/
static int smk_parse_label_list(char *data, struct list_head *list)
{
char *tok;
struct smack_known *skp;
struct smack_known_list_elem *sklep;
while ((tok = strsep(&data, " ")) != NULL) {
if (!*tok)
continue;
skp = smk_import_entry(tok, 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sklep = kzalloc(sizeof(*sklep), GFP_KERNEL);
if (sklep == NULL)
return -ENOMEM;
sklep->smk_label = skp;
list_add(&sklep->list, list);
}
return 0;
}
/**
* smk_destroy_label_list - destroy a list of smack_known_list_elem
* @list: header pointer of the list to destroy
*/
void smk_destroy_label_list(struct list_head *list)
{
struct smack_known_list_elem *sklep;
struct smack_known_list_elem *sklep2;
list_for_each_entry_safe(sklep, sklep2, list, list)
kfree(sklep);
INIT_LIST_HEAD(list);
}
/**
* smk_write_onlycap - write() for smackfs/onlycap
* @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_onlycap(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char *data;
LIST_HEAD(list_tmp);
int rc;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (count > PAGE_SIZE)
return -EINVAL;
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
rc = smk_parse_label_list(data, &list_tmp);
kfree(data);
/*
* Clear the smack_onlycap on invalid label errors. This means
* that we can pass a null string to unset the onlycap value.
*
* Importing will also reject a label beginning with '-',
* so "-usecapabilities" will also work.
*
* But do so only on invalid label, not on system errors.
* The invalid label must be first to count as clearing attempt.
*/
if (!rc || (rc == -EINVAL && list_empty(&list_tmp))) {
mutex_lock(&smack_onlycap_lock);
smk_list_swap_rcu(&smack_onlycap_list, &list_tmp);
mutex_unlock(&smack_onlycap_lock);
rc = count;
}
smk_destroy_label_list(&list_tmp);
return rc;
}
static const struct file_operations smk_onlycap_ops = {
.open = smk_open_onlycap,
.read = seq_read,
.write = smk_write_onlycap,
.llseek = seq_lseek,
.release = seq_release,
};
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
/**
* smk_read_unconfined - read() for smackfs/unconfined
* @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_unconfined(struct file *filp, char __user *buf,
size_t cn, loff_t *ppos)
{
char *smack = "";
ssize_t rc = -EINVAL;
int asize;
if (*ppos != 0)
return 0;
if (smack_unconfined != NULL)
smack = smack_unconfined->smk_known;
asize = strlen(smack) + 1;
if (cn >= asize)
rc = simple_read_from_buffer(buf, cn, ppos, smack, asize);
return rc;
}
/**
* smk_write_unconfined - write() for smackfs/unconfined
* @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_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))
return -EPERM;
if (count > PAGE_SIZE)
return -EINVAL;
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
/*
* Clear the smack_unconfined on invalid label errors. This means
* that we can pass a null string to unset the unconfined value.
*
* Importing will also reject a label beginning with '-',
* so "-confine" will also work.
*
* But do so only on invalid label, not on system errors.
*/
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;
}
static const struct file_operations smk_unconfined_ops = {
.read = smk_read_unconfined,
.write = smk_write_unconfined,
.llseek = default_llseek,
};
#endif /* CONFIG_SECURITY_SMACK_BRINGUP */
/**
* smk_read_logging - read() for /smack/logging
* @filp: file pointer, not actually used
* @buf: where to put the result
* @count: maximum to send along
* @ppos: where to start
*
* Returns number of bytes read or error code, as appropriate
*/
static ssize_t smk_read_logging(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char temp[32];
ssize_t rc;
if (*ppos != 0)
return 0;
sprintf(temp, "%d\n", log_policy);
rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
return rc;
}
/**
* smk_write_logging - write() for /smack/logging
* @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_logging(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char temp[32];
int i;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (count >= sizeof(temp) || count == 0)
return -EINVAL;
if (copy_from_user(temp, buf, count) != 0)
return -EFAULT;
temp[count] = '\0';
if (sscanf(temp, "%d", &i) != 1)
return -EINVAL;
if (i < 0 || i > 3)
return -EINVAL;
log_policy = i;
return count;
}
static const struct file_operations smk_logging_ops = {
.read = smk_read_logging,
.write = smk_write_logging,
.llseek = default_llseek,
};
/*
* Seq_file read operations for /smack/load-self
*/
static void *load_self_seq_start(struct seq_file *s, loff_t *pos)
{
struct task_smack *tsp = smack_cred(current_cred());
return smk_seq_start(s, pos, &tsp->smk_rules);
}
static void *load_self_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
struct task_smack *tsp = smack_cred(current_cred());
return smk_seq_next(s, v, pos, &tsp->smk_rules);
}
static int load_self_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smack_rule *srp =
list_entry_rcu(list, struct smack_rule, list);
smk_rule_show(s, srp, SMK_LABELLEN);
return 0;
}
static const struct seq_operations load_self_seq_ops = {
.start = load_self_seq_start,
.next = load_self_seq_next,
.show = load_self_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_load_self - open() for /smack/load-self2
* @inode: inode structure representing file
* @file: "load" file pointer
*
* For reading, use load_seq_* seq_file reading operations.
*/
static int smk_open_load_self(struct inode *inode, struct file *file)
{
return seq_open(file, &load_self_seq_ops);
}
/**
* smk_write_load_self - write() for /smack/load-self
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start - must be 0
*
*/
static ssize_t smk_write_load_self(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct task_smack *tsp = smack_cred(current_cred());
return smk_write_rules_list(file, buf, count, ppos, &tsp->smk_rules,
&tsp->smk_rules_lock, SMK_FIXED24_FMT);
}
static const struct file_operations smk_load_self_ops = {
.open = smk_open_load_self,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_load_self,
.release = seq_release,
};
/**
* smk_user_access - handle access check transaction
* @file: file pointer
* @buf: data from user space
* @count: bytes sent
* @ppos: where to start - must be 0
* @format: /smack/load or /smack/load2 or /smack/change-rule format.
*/
static ssize_t smk_user_access(struct file *file, const char __user *buf,
size_t count, loff_t *ppos, int format)
{
struct smack_parsed_rule rule;
char *data;
int res;
data = simple_transaction_get(file, buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
if (format == SMK_FIXED24_FMT) {
if (count < SMK_LOADLEN)
return -EINVAL;
res = smk_parse_rule(data, &rule, 0);
} else {
/*
* simple_transaction_get() returns null-terminated data
*/
res = smk_parse_long_rule(data, &rule, 0, 3);
}
if (res >= 0)
res = smk_access(rule.smk_subject, rule.smk_object,
rule.smk_access1, NULL);
else if (res != -ENOENT)
return res;
/*
* smk_access() can return a value > 0 in the "bringup" case.
*/
data[0] = res >= 0 ? '1' : '0';
data[1] = '\0';
simple_transaction_set(file, 2);
if (format == SMK_FIXED24_FMT)
return SMK_LOADLEN;
return count;
}
/**
* smk_write_access - handle access check transaction
* @file: file pointer
* @buf: data from user space
* @count: bytes sent
* @ppos: where to start - must be 0
*/
static ssize_t smk_write_access(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
return smk_user_access(file, buf, count, ppos, SMK_FIXED24_FMT);
}
static const struct file_operations smk_access_ops = {
.write = smk_write_access,
.read = simple_transaction_read,
.release = simple_transaction_release,
.llseek = generic_file_llseek,
};
/*
* Seq_file read operations for /smack/load2
*/
static int load2_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smack_rule *srp;
struct smack_known *skp =
list_entry_rcu(list, struct smack_known, list);
list_for_each_entry_rcu(srp, &skp->smk_rules, list)
smk_rule_show(s, srp, SMK_LONGLABEL);
return 0;
}
static const struct seq_operations load2_seq_ops = {
.start = load2_seq_start,
.next = load2_seq_next,
.show = load2_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_load2 - open() for /smack/load2
* @inode: inode structure representing file
* @file: "load2" file pointer
*
* For reading, use load2_seq_* seq_file reading operations.
*/
static int smk_open_load2(struct inode *inode, struct file *file)
{
return seq_open(file, &load2_seq_ops);
}
/**
* smk_write_load2 - write() for /smack/load2
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start - must be 0
*
*/
static ssize_t smk_write_load2(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
/*
* Must have privilege.
*/
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
return smk_write_rules_list(file, buf, count, ppos, NULL, NULL,
SMK_LONG_FMT);
}
static const struct file_operations smk_load2_ops = {
.open = smk_open_load2,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_load2,
.release = seq_release,
};
/*
* Seq_file read operations for /smack/load-self2
*/
static void *load_self2_seq_start(struct seq_file *s, loff_t *pos)
{
struct task_smack *tsp = smack_cred(current_cred());
return smk_seq_start(s, pos, &tsp->smk_rules);
}
static void *load_self2_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
struct task_smack *tsp = smack_cred(current_cred());
return smk_seq_next(s, v, pos, &tsp->smk_rules);
}
static int load_self2_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smack_rule *srp =
list_entry_rcu(list, struct smack_rule, list);
smk_rule_show(s, srp, SMK_LONGLABEL);
return 0;
}
static const struct seq_operations load_self2_seq_ops = {
.start = load_self2_seq_start,
.next = load_self2_seq_next,
.show = load_self2_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_load_self2 - open() for /smack/load-self2
* @inode: inode structure representing file
* @file: "load" file pointer
*
* For reading, use load_seq_* seq_file reading operations.
*/
static int smk_open_load_self2(struct inode *inode, struct file *file)
{
return seq_open(file, &load_self2_seq_ops);
}
/**
* smk_write_load_self2 - write() for /smack/load-self2
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start - must be 0
*
*/
static ssize_t smk_write_load_self2(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct task_smack *tsp = smack_cred(current_cred());
return smk_write_rules_list(file, buf, count, ppos, &tsp->smk_rules,
&tsp->smk_rules_lock, SMK_LONG_FMT);
}
static const struct file_operations smk_load_self2_ops = {
.open = smk_open_load_self2,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_load_self2,
.release = seq_release,
};
/**
* smk_write_access2 - handle access check transaction
* @file: file pointer
* @buf: data from user space
* @count: bytes sent
* @ppos: where to start - must be 0
*/
static ssize_t smk_write_access2(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
return smk_user_access(file, buf, count, ppos, SMK_LONG_FMT);
}
static const struct file_operations smk_access2_ops = {
.write = smk_write_access2,
.read = simple_transaction_read,
.release = simple_transaction_release,
.llseek = generic_file_llseek,
};
/**
* smk_write_revoke_subj - write() for /smack/revoke-subject
* @file: file pointer
* @buf: data from user space
* @count: bytes sent
* @ppos: where to start - must be 0
*/
static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char *data;
const char *cp;
struct smack_known *skp;
struct smack_rule *sp;
struct list_head *rule_list;
struct mutex *rule_lock;
int rc = count;
if (*ppos != 0)
return -EINVAL;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (count == 0 || count > SMK_LONGLABEL)
return -EINVAL;
data = memdup_user(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
cp = smk_parse_smack(data, count);
if (IS_ERR(cp)) {
rc = PTR_ERR(cp);
goto out_data;
}
skp = smk_find_entry(cp);
if (skp == NULL)
goto out_cp;
rule_list = &skp->smk_rules;
rule_lock = &skp->smk_rules_lock;
mutex_lock(rule_lock);
list_for_each_entry_rcu(sp, rule_list, list)
sp->smk_access = 0;
mutex_unlock(rule_lock);
out_cp:
kfree(cp);
out_data:
kfree(data);
return rc;
}
static const struct file_operations smk_revoke_subj_ops = {
.write = smk_write_revoke_subj,
.read = simple_transaction_read,
.release = simple_transaction_release,
.llseek = generic_file_llseek,
};
/**
* smk_init_sysfs - initialize /sys/fs/smackfs
*
*/
static int smk_init_sysfs(void)
{
return sysfs_create_mount_point(fs_kobj, "smackfs");
}
/**
* smk_write_change_rule - write() for /smack/change-rule
* @file: file pointer
* @buf: data from user space
* @count: bytes sent
* @ppos: where to start - must be 0
*/
static ssize_t smk_write_change_rule(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
/*
* Must have privilege.
*/
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
return smk_write_rules_list(file, buf, count, ppos, NULL, NULL,
SMK_CHANGE_FMT);
}
static const struct file_operations smk_change_rule_ops = {
.write = smk_write_change_rule,
.read = simple_transaction_read,
.release = simple_transaction_release,
.llseek = generic_file_llseek,
};
/**
* 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;
/* Enough data must be present */
if (count == 0 || count > PAGE_SIZE)
return -EINVAL;
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
skp = smk_import_entry(data, count);
if (IS_ERR(skp))
rc = PTR_ERR(skp);
else
smack_syslog_label = skp;
kfree(data);
return rc;
}
static const struct file_operations smk_syslog_ops = {
.read = smk_read_syslog,
.write = smk_write_syslog,
.llseek = default_llseek,
};
/*
* Seq_file read operations for /smack/relabel-self
*/
static void *relabel_self_seq_start(struct seq_file *s, loff_t *pos)
{
struct task_smack *tsp = smack_cred(current_cred());
return smk_seq_start(s, pos, &tsp->smk_relabel);
}
static void *relabel_self_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
struct task_smack *tsp = smack_cred(current_cred());
return smk_seq_next(s, v, pos, &tsp->smk_relabel);
}
static int relabel_self_seq_show(struct seq_file *s, void *v)
{
struct list_head *list = v;
struct smack_known_list_elem *sklep =
list_entry(list, struct smack_known_list_elem, list);
seq_puts(s, sklep->smk_label->smk_known);
seq_putc(s, ' ');
return 0;
}
static const struct seq_operations relabel_self_seq_ops = {
.start = relabel_self_seq_start,
.next = relabel_self_seq_next,
.show = relabel_self_seq_show,
.stop = smk_seq_stop,
};
/**
* smk_open_relabel_self - open() for /smack/relabel-self
* @inode: inode structure representing file
* @file: "relabel-self" file pointer
*
* Connect our relabel_self_seq_* operations with /smack/relabel-self
* file_operations
*/
static int smk_open_relabel_self(struct inode *inode, struct file *file)
{
return seq_open(file, &relabel_self_seq_ops);
}
/**
* smk_write_relabel_self - write() for /smack/relabel-self
* @file: file pointer, not actually used
* @buf: where to get the data from
* @count: bytes sent
* @ppos: where to start - must be 0
*
*/
static ssize_t smk_write_relabel_self(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char *data;
int rc;
LIST_HEAD(list_tmp);
/*
* Must have privilege.
*/
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
/*
* No partial write.
* Enough data must be present.
*/
if (*ppos != 0)
return -EINVAL;
if (count == 0 || count > PAGE_SIZE)
return -EINVAL;
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
rc = smk_parse_label_list(data, &list_tmp);
kfree(data);
if (!rc || (rc == -EINVAL && list_empty(&list_tmp))) {
struct cred *new;
struct task_smack *tsp;
new = prepare_creds();
if (!new) {
rc = -ENOMEM;
goto out;
}
tsp = smack_cred(new);
smk_destroy_label_list(&tsp->smk_relabel);
list_splice(&list_tmp, &tsp->smk_relabel);
commit_creds(new);
return count;
}
out:
smk_destroy_label_list(&list_tmp);
return rc;
}
static const struct file_operations smk_relabel_self_ops = {
.open = smk_open_relabel_self,
.read = seq_read,
.llseek = seq_lseek,
.write = smk_write_relabel_self,
.release = seq_release,
};
/**
* smk_read_ptrace - read() for /smack/ptrace
* @filp: file pointer, not actually used
* @buf: where to put the result
* @count: maximum to send along
* @ppos: where to start
*
* Returns number of bytes read or error code, as appropriate
*/
static ssize_t smk_read_ptrace(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char temp[32];
ssize_t rc;
if (*ppos != 0)
return 0;
sprintf(temp, "%d\n", smack_ptrace_rule);
rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
return rc;
}
/**
* smk_write_ptrace - write() for /smack/ptrace
* @file: file pointer
* @buf: data from user space
* @count: bytes sent
* @ppos: where to start - must be 0
*/
static ssize_t smk_write_ptrace(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char temp[32];
int i;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (*ppos != 0 || count >= sizeof(temp) || count == 0)
return -EINVAL;
if (copy_from_user(temp, buf, count) != 0)
return -EFAULT;
temp[count] = '\0';
if (sscanf(temp, "%d", &i) != 1)
return -EINVAL;
if (i < SMACK_PTRACE_DEFAULT || i > SMACK_PTRACE_MAX)
return -EINVAL;
smack_ptrace_rule = i;
return count;
}
static const struct file_operations smk_ptrace_ops = {
.write = smk_write_ptrace,
.read = smk_read_ptrace,
.llseek = default_llseek,
};
/**
* smk_fill_super - fill the smackfs superblock
* @sb: the empty superblock
* @fc: unused
*
* Fill in the well known entries for the smack filesystem
*
* Returns 0 on success, an error code on failure
*/
static int smk_fill_super(struct super_block *sb, struct fs_context *fc)
{
int rc;
static const struct tree_descr smack_files[] = {
[SMK_LOAD] = {
"load", &smk_load_ops, S_IRUGO|S_IWUSR},
[SMK_CIPSO] = {
"cipso", &smk_cipso_ops, S_IRUGO|S_IWUSR},
[SMK_DOI] = {
"doi", &smk_doi_ops, S_IRUGO|S_IWUSR},
[SMK_DIRECT] = {
"direct", &smk_direct_ops, S_IRUGO|S_IWUSR},
[SMK_AMBIENT] = {
"ambient", &smk_ambient_ops, S_IRUGO|S_IWUSR},
[SMK_NET4ADDR] = {
"netlabel", &smk_net4addr_ops, S_IRUGO|S_IWUSR},
[SMK_ONLYCAP] = {
"onlycap", &smk_onlycap_ops, S_IRUGO|S_IWUSR},
[SMK_LOGGING] = {
"logging", &smk_logging_ops, S_IRUGO|S_IWUSR},
[SMK_LOAD_SELF] = {
"load-self", &smk_load_self_ops, S_IRUGO|S_IWUGO},
[SMK_ACCESSES] = {
"access", &smk_access_ops, S_IRUGO|S_IWUGO},
[SMK_MAPPED] = {
"mapped", &smk_mapped_ops, S_IRUGO|S_IWUSR},
[SMK_LOAD2] = {
"load2", &smk_load2_ops, S_IRUGO|S_IWUSR},
[SMK_LOAD_SELF2] = {
"load-self2", &smk_load_self2_ops, S_IRUGO|S_IWUGO},
[SMK_ACCESS2] = {
"access2", &smk_access2_ops, S_IRUGO|S_IWUGO},
[SMK_CIPSO2] = {
"cipso2", &smk_cipso2_ops, S_IRUGO|S_IWUSR},
[SMK_REVOKE_SUBJ] = {
"revoke-subject", &smk_revoke_subj_ops,
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},
[SMK_PTRACE] = {
"ptrace", &smk_ptrace_ops, S_IRUGO|S_IWUSR},
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
[SMK_UNCONFINED] = {
"unconfined", &smk_unconfined_ops, S_IRUGO|S_IWUSR},
#endif
#if IS_ENABLED(CONFIG_IPV6)
[SMK_NET6ADDR] = {
"ipv6host", &smk_net6addr_ops, S_IRUGO|S_IWUSR},
#endif /* CONFIG_IPV6 */
[SMK_RELABEL_SELF] = {
"relabel-self", &smk_relabel_self_ops,
S_IRUGO|S_IWUGO},
/* last one */
{""}
};
rc = simple_fill_super(sb, SMACK_MAGIC, smack_files);
if (rc != 0) {
printk(KERN_ERR "%s failed %d while creating inodes\n",
__func__, rc);
return rc;
}
return 0;
}
/**
* smk_get_tree - get the smackfs superblock
* @fc: The mount context, including any options
*
* Just passes everything along.
*
* Returns what the lower level code does.
*/
static int smk_get_tree(struct fs_context *fc)
{
return get_tree_single(fc, smk_fill_super);
}
static const struct fs_context_operations smk_context_ops = {
.get_tree = smk_get_tree,
};
/**
* smk_init_fs_context - Initialise a filesystem context for smackfs
* @fc: The blank mount context
*/
static int smk_init_fs_context(struct fs_context *fc)
{
fc->ops = &smk_context_ops;
return 0;
}
static struct file_system_type smk_fs_type = {
.name = "smackfs",
.init_fs_context = smk_init_fs_context,
.kill_sb = kill_litter_super,
};
static struct vfsmount *smackfs_mount;
/**
* init_smk_fs - get the smackfs superblock
*
* register the smackfs
*
* Do not register smackfs if Smack wasn't enabled
* on boot. We can not put this method normally under the
* smack_init() code path since the security subsystem get
* initialized before the vfs caches.
*
* Returns true if we were not chosen on boot or if
* we were chosen and filesystem registration succeeded.
*/
static int __init init_smk_fs(void)
{
int err;
int rc;
if (smack_enabled == 0)
return 0;
err = smk_init_sysfs();
if (err)
printk(KERN_ERR "smackfs: sysfs mountpoint problem.\n");
err = register_filesystem(&smk_fs_type);
if (!err) {
smackfs_mount = kern_mount(&smk_fs_type);
if (IS_ERR(smackfs_mount)) {
printk(KERN_ERR "smackfs: could not mount!\n");
err = PTR_ERR(smackfs_mount);
smackfs_mount = NULL;
}
}
smk_cipso_doi();
smk_unlbl_ambient(NULL);
rc = smack_populate_secattr(&smack_known_floor);
if (err == 0 && rc < 0)
err = rc;
rc = smack_populate_secattr(&smack_known_hat);
if (err == 0 && rc < 0)
err = rc;
rc = smack_populate_secattr(&smack_known_huh);
if (err == 0 && rc < 0)
err = rc;
rc = smack_populate_secattr(&smack_known_star);
if (err == 0 && rc < 0)
err = rc;
rc = smack_populate_secattr(&smack_known_web);
if (err == 0 && rc < 0)
err = rc;
return err;
}
__initcall(init_smk_fs);
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