[PATCH 31/39] convert selinuxfs
Al Viro
viro at zeniv.linux.org.uk
Mon Sep 22 13:52:18 AEST 2025
On Sun, Sep 21, 2025 at 10:50:02PM -0400, Paul Moore wrote:
> Looks good to me, ACK below. For me personally, it's a bit late to
> take non-bugfix stuff for the upcoming merge window so I would defer
> this for a few weeks, but if you want to take it now that's your call.
> Also your call if you would prefer this to go in with the rest of the
> patchset you've working on, or if you want me to take it via the
> SELinux tree. Let me know.
Seeing that it's already a 41-commit patchset (rpc_pipe conversion pulled
in, now +1 from this split) with several more in the pipeline (securityfs
conversion, for starters) and it's -rc7...
I think I'll post v2 in the middle of the week, but aim for the next
cycle. Rebase to -rc1 as soon as it comes, post v3 for review and testing,
then shove it into -next.
Especially since #work.nfsctl is in -next, so hopefully by -rc1 there won't
be any need to put merges in the middle of the series, with conversion of
nfsctl included into the series, bringing with it removal of kill_litter_super()
and (hopefully) "give configfs and apparmorfs private copies of simple_unlink()
and simple_rmdir() doing dput() instead of d_make_discardable(), then make
d_make_discardable() complain about being called on non-persistent dentries".
Speaking of additional patches into that series: AFAICS there's no reason
for selinuxfs to allocate dentry before the inode. Doing it the other way
round simplifies the things quite a bit, IMO. Something like this (as followup
to the previous patch):
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 482a2cac9640..7bee2d8bdec5 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -1197,6 +1197,25 @@ static struct inode *sel_make_inode(struct super_block *sb, umode_t mode)
return ret;
}
+static struct dentry *sel_attach(struct dentry *parent, const char *name,
+ struct inode *inode)
+{
+ struct dentry *dentry = d_alloc_name(parent, name);
+ if (unlikely(!dentry)) {
+ iput(inode);
+ return ERR_PTR(-ENOMEM);
+ }
+ d_add(dentry, inode);
+ return dentry;
+}
+
+static int sel_attach_file(struct dentry *parent, const char *name,
+ struct inode *inode)
+{
+ struct dentry *dentry = sel_attach(parent, name, inode);
+ return PTR_ERR_OR_ZERO(dentry);
+}
+
static ssize_t sel_read_bool(struct file *filep, char __user *buf,
size_t count, loff_t *ppos)
{
@@ -1364,8 +1383,7 @@ static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_
*bool_num = num;
*bool_pending_names = names;
- for (i = 0; i < num; i++) {
- struct dentry *dentry;
+ for (i = 0; !ret && i < num; i++) {
struct inode *inode;
struct inode_security_struct *isec;
ssize_t len;
@@ -1376,15 +1394,9 @@ static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_
ret = -ENAMETOOLONG;
break;
}
- dentry = d_alloc_name(bool_dir, names[i]);
- if (!dentry) {
- ret = -ENOMEM;
- break;
- }
inode = sel_make_inode(bool_dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
if (!inode) {
- dput(dentry);
ret = -ENOMEM;
break;
}
@@ -1402,7 +1414,8 @@ static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_
isec->initialized = LABEL_INITIALIZED;
inode->i_fop = &sel_bool_ops;
inode->i_ino = i|SEL_BOOL_INO_OFFSET;
- d_add(dentry, inode);
+
+ ret = sel_attach_file(bool_dir, names[i], inode);
}
out:
free_page((unsigned long)page);
@@ -1587,6 +1600,7 @@ static int sel_make_avc_files(struct dentry *dir)
struct super_block *sb = dir->d_sb;
struct selinux_fs_info *fsi = sb->s_fs_info;
unsigned int i;
+ int err = 0;
static const struct tree_descr files[] = {
{ "cache_threshold",
&sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
@@ -1596,26 +1610,20 @@ static int sel_make_avc_files(struct dentry *dir)
#endif
};
- for (i = 0; i < ARRAY_SIZE(files); i++) {
+ for (i = 0; !err && i < ARRAY_SIZE(files); i++) {
struct inode *inode;
- struct dentry *dentry;
-
- dentry = d_alloc_name(dir, files[i].name);
- if (!dentry)
- return -ENOMEM;
inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
- if (!inode) {
- dput(dentry);
+ if (!inode)
return -ENOMEM;
- }
inode->i_fop = files[i].ops;
inode->i_ino = ++fsi->last_ino;
- d_add(dentry, inode);
+
+ err = sel_attach_file(dir, files[i].name, inode);
}
- return 0;
+ return err;
}
static int sel_make_ss_files(struct dentry *dir)
@@ -1623,30 +1631,25 @@ static int sel_make_ss_files(struct dentry *dir)
struct super_block *sb = dir->d_sb;
struct selinux_fs_info *fsi = sb->s_fs_info;
unsigned int i;
+ int err = 0;
static const struct tree_descr files[] = {
{ "sidtab_hash_stats", &sel_sidtab_hash_stats_ops, S_IRUGO },
};
- for (i = 0; i < ARRAY_SIZE(files); i++) {
+ for (i = 0; !err && i < ARRAY_SIZE(files); i++) {
struct inode *inode;
- struct dentry *dentry;
-
- dentry = d_alloc_name(dir, files[i].name);
- if (!dentry)
- return -ENOMEM;
inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
- if (!inode) {
- dput(dentry);
+ if (!inode)
return -ENOMEM;
- }
inode->i_fop = files[i].ops;
inode->i_ino = ++fsi->last_ino;
- d_add(dentry, inode);
+
+ err = sel_attach_file(dir, files[i].name, inode);
}
- return 0;
+ return err;
}
static ssize_t sel_read_initcon(struct file *file, char __user *buf,
@@ -1674,30 +1677,25 @@ static const struct file_operations sel_initcon_ops = {
static int sel_make_initcon_files(struct dentry *dir)
{
unsigned int i;
+ int err = 0;
- for (i = 1; i <= SECINITSID_NUM; i++) {
- struct inode *inode;
- struct dentry *dentry;
+ for (i = 1; !err && i <= SECINITSID_NUM; i++) {
const char *s = security_get_initial_sid_context(i);
+ struct inode *inode;
if (!s)
continue;
- dentry = d_alloc_name(dir, s);
- if (!dentry)
- return -ENOMEM;
inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
- if (!inode) {
- dput(dentry);
+ if (!inode)
return -ENOMEM;
- }
inode->i_fop = &sel_initcon_ops;
inode->i_ino = i|SEL_INITCON_INO_OFFSET;
- d_add(dentry, inode);
+ err = sel_attach_file(dir, s, inode);
}
- return 0;
+ return err;
}
static inline unsigned long sel_class_to_ino(u16 class)
@@ -1779,29 +1777,21 @@ static int sel_make_perm_files(struct selinux_policy *newpolicy,
if (rc)
return rc;
- for (i = 0; i < nperms; i++) {
+ for (i = 0; !rc && i < nperms; i++) {
struct inode *inode;
- struct dentry *dentry;
- rc = -ENOMEM;
- dentry = d_alloc_name(dir, perms[i]);
- if (!dentry)
- goto out;
-
- rc = -ENOMEM;
inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
if (!inode) {
- dput(dentry);
- goto out;
+ rc = -ENOMEM;
+ break;
}
inode->i_fop = &sel_perm_ops;
/* i+1 since perm values are 1-indexed */
inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
- d_add(dentry, inode);
+
+ rc = sel_attach_file(dir, perms[i], inode);
}
- rc = 0;
-out:
for (i = 0; i < nperms; i++)
kfree(perms[i]);
kfree(perms);
@@ -1816,20 +1806,18 @@ static int sel_make_class_dir_entries(struct selinux_policy *newpolicy,
struct selinux_fs_info *fsi = sb->s_fs_info;
struct dentry *dentry = NULL;
struct inode *inode = NULL;
-
- dentry = d_alloc_name(dir, "index");
- if (!dentry)
- return -ENOMEM;
+ int err;
inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
- if (!inode) {
- dput(dentry);
+ if (!inode)
return -ENOMEM;
- }
inode->i_fop = &sel_class_ops;
inode->i_ino = sel_class_to_ino(index);
- d_add(dentry, inode);
+
+ err = sel_attach_file(dir, "index", inode);
+ if (err)
+ return err;
dentry = sel_make_dir(dir, "perms", &fsi->last_class_ino);
if (IS_ERR(dentry))
@@ -1881,58 +1869,47 @@ static int sel_make_policycap(struct dentry *dir)
{
struct super_block *sb = dir->d_sb;
unsigned int iter;
- struct dentry *dentry = NULL;
struct inode *inode = NULL;
+ int err = 0;
+
+ for (iter = 0; !err && iter <= POLICYDB_CAP_MAX; iter++) {
+ const char *name;
- for (iter = 0; iter <= POLICYDB_CAP_MAX; iter++) {
if (iter < ARRAY_SIZE(selinux_policycap_names))
- dentry = d_alloc_name(dir,
- selinux_policycap_names[iter]);
+ name = selinux_policycap_names[iter];
else
- dentry = d_alloc_name(dir, "unknown");
-
- if (dentry == NULL)
- return -ENOMEM;
+ name = "unknown";
inode = sel_make_inode(sb, S_IFREG | 0444);
- if (inode == NULL) {
- dput(dentry);
+ if (!inode)
return -ENOMEM;
- }
inode->i_fop = &sel_policycap_ops;
inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
- d_add(dentry, inode);
+ err = sel_attach_file(dir, name, inode);
}
- return 0;
+ return err;
}
static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
unsigned long *ino)
{
- struct dentry *dentry = d_alloc_name(dir, name);
struct inode *inode;
- if (!dentry)
- return ERR_PTR(-ENOMEM);
-
inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
- if (!inode) {
- dput(dentry);
+ if (!inode)
return ERR_PTR(-ENOMEM);
- }
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
inode->i_ino = ++(*ino);
/* directory inodes start off with i_nlink == 2 (for "." entry) */
inc_nlink(inode);
- d_add(dentry, inode);
/* bump link count on parent directory, too */
inc_nlink(d_inode(dir));
- return dentry;
+ return sel_attach(dir, name, inode);
}
static int reject_all(struct mnt_idmap *idmap, struct inode *inode, int mask)
@@ -2020,17 +1997,10 @@ static int sel_fill_super(struct super_block *sb, struct fs_context *fc)
goto err;
}
- ret = -ENOMEM;
- dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
- if (!dentry)
- goto err;
-
ret = -ENOMEM;
inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
- if (!inode) {
- dput(dentry);
+ if (!inode)
goto err;
- }
inode->i_ino = ++fsi->last_ino;
isec = selinux_inode(inode);
@@ -2039,7 +2009,9 @@ static int sel_fill_super(struct super_block *sb, struct fs_context *fc)
isec->initialized = LABEL_INITIALIZED;
init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
- d_add(dentry, inode);
+ ret = sel_attach_file(sb->s_root, NULL_FILE_NAME, inode);
+ if (ret)
+ goto err;
dentry = sel_make_dir(sb->s_root, "avc", &fsi->last_ino);
if (IS_ERR(dentry)) {
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