[PATCH 1/2] smack: deduplicate smackfs/{direct, mapped} file_operations
Konstantin Andreev
andreev at swemel.ru
Sun May 24 22:37:48 UTC 2026
The file_operations for smackfs/direct and smackfs/mapped are
identical up to a textual replacement of "direct" with "mapped"
This patch combines two instances of file_operations into one,
handling both files.
Fixes: f7112e6c9abf ("Smack: allow for significantly longer Smack labels v4")
Signed-off-by: Konstantin Andreev <andreev at swemel.ru>
---
security/smack/smack.h | 5 +-
security/smack/smackfs.c | 135 ++++++++++++---------------------------
2 files changed, 43 insertions(+), 97 deletions(-)
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 9b9eb262fe33..6febc2ecdfe8 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -317,8 +317,9 @@ int smack_populate_secattr(struct smack_known *skp);
* Shared data.
*/
extern int smack_enabled __initdata;
-extern int smack_cipso_direct;
-extern int smack_cipso_mapped;
+extern int smack_cipso_auto_level[2];
+#define smack_cipso_direct (+smack_cipso_auto_level[0])
+#define smack_cipso_mapped (+smack_cipso_auto_level[1])
extern struct smack_known *smack_net_ambient;
extern struct smack_known *smack_syslog_label;
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index f60d5469043e..946405645d5a 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -83,18 +83,27 @@ static DEFINE_MUTEX(smk_net6addr_lock);
struct smack_known *smack_net_ambient;
/*
- * This is the level in a CIPSO header that indicates a
+ * Sensitivity levels for automatically created CIPSO labels.
+ * See smack_access.c`smack_populate_secattr()
+ *
+ * [0] "direct" labeling, label length < SMK_CIPSOLEN(24):
* 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
+ *
+ * [1] "mapped" labeling, label length >= SMK_CIPSOLEN(24):
* secid is contained directly in the category set.
* It can be reset via smackfs/mapped
*/
-int smack_cipso_mapped = SMACK_CIPSO_MAPPED_DEFAULT;
+int smack_cipso_auto_level[2] = {
+ SMACK_CIPSO_DIRECT_DEFAULT,
+ SMACK_CIPSO_MAPPED_DEFAULT,
+};
+
+static int
+smk_cipso_auto_level_idx(const struct file *file)
+{
+ return (file_inode(file)->i_ino != SMK_DIRECT);
+}
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
/*
@@ -1621,15 +1630,15 @@ static const struct file_operations smk_doi_ops = {
};
/**
- * smk_read_direct - read() for /smack/direct
- * @filp: file pointer, not actually used
+ * smk_read_cipso_auto_level - read() for smackfs/direct and smackfs/mapped
+ * @filp: file pointer
* @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,
+static ssize_t smk_read_cipso_auto_level(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char temp[80];
@@ -1638,26 +1647,28 @@ static ssize_t smk_read_direct(struct file *filp, char __user *buf,
if (*ppos != 0)
return 0;
- sprintf(temp, "%d", smack_cipso_direct);
+ sprintf(temp, "%d", smack_cipso_auto_level[
+ smk_cipso_auto_level_idx(filp)]);
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
+ * smk_write_cipso_auto_level - write() for smackfs/direct and smackfs/mapped
+ * @filp: file pointer
* @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)
+static ssize_t
+smk_write_cipso_auto_level(struct file *filp, const char __user *buf,
+ size_t count, loff_t *ppos)
{
struct smack_known *skp;
- int i, ret;
+ int i, ret, idx, old_lvl;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
@@ -1669,94 +1680,28 @@ static ssize_t smk_write_direct(struct file *file, const char __user *buf,
/*
* 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.
+ * set up to be "auto" level when they were created.
*/
- if (smack_cipso_direct != i) {
+ idx = smk_cipso_auto_level_idx(filp);
+ old_lvl = smack_cipso_auto_level[idx];
+
+ if (old_lvl != 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)
+ old_lvl)
skp->smk_netlabel.attr.mls.lvl = i;
- smack_cipso_direct = i;
+ smack_cipso_auto_level[idx] = 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;
- int i, ret;
-
- if (!smack_privileged(CAP_MAC_ADMIN))
- return -EPERM;
-
- ret = kstrtos32_from_user(buf, count, 10, &i);
- if (unlikely(ret))
- return ret;
-
- /*
- * 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,
+static const struct file_operations
+smk_cipso_auto_level_ops = {
+ .read = smk_read_cipso_auto_level,
+ .write = smk_write_cipso_auto_level,
.llseek = default_llseek,
};
@@ -2851,7 +2796,7 @@ static int smk_fill_super(struct super_block *sb, struct fs_context *fc)
[SMK_DOI] = {
"doi", &smk_doi_ops, S_IRUGO|S_IWUSR},
[SMK_DIRECT] = {
- "direct", &smk_direct_ops, S_IRUGO|S_IWUSR},
+ "direct", &smk_cipso_auto_level_ops, 0644},
[SMK_AMBIENT] = {
"ambient", &smk_ambient_ops, S_IRUGO|S_IWUSR},
[SMK_NET4ADDR] = {
@@ -2867,7 +2812,7 @@ static int smk_fill_super(struct super_block *sb, struct fs_context *fc)
[SMK_ACCESSES] = {
"access", &smk_access_ops, S_IRUGO|S_IWUGO},
[SMK_MAPPED] = {
- "mapped", &smk_mapped_ops, S_IRUGO|S_IWUSR},
+ "mapped", &smk_cipso_auto_level_ops, 0644},
[SMK_LOAD2] = {
"load2", &smk_load2_ops, S_IRUGO|S_IWUSR},
[SMK_LOAD_SELF2] = {
--
2.47.3
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