PATCH v1 08/22] SELinux: Abstract use of inode security blob

From: Casey Schaufler
Date: Mon Jul 16 2018 - 14:23:16 EST


SELinux: Abstract use of inode security blob

Don't use the inode->i_security pointer directly.
Provide a helper function that provides the security blob pointer.

Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
---
security/selinux/hooks.c | 26 +++++++++++++-------------
security/selinux/include/objsec.h | 6 ++++++
security/selinux/selinuxfs.c | 4 ++--
3 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ea9557ad7b7a..aafd1506fe6b 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -276,7 +276,7 @@ static int __inode_security_revalidate(struct inode *inode,
struct dentry *dentry,
bool may_sleep)
{
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = selinux_inode(inode);

might_sleep_if(may_sleep);

@@ -297,7 +297,7 @@ static int __inode_security_revalidate(struct inode *inode,

static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
{
- return inode->i_security;
+ return selinux_inode(inode);
}

static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
@@ -307,7 +307,7 @@ static struct inode_security_struct *inode_security_rcu(struct inode *inode, boo
error = __inode_security_revalidate(inode, NULL, !rcu);
if (error)
return ERR_PTR(error);
- return inode->i_security;
+ return selinux_inode(inode);
}

/*
@@ -316,14 +316,14 @@ static struct inode_security_struct *inode_security_rcu(struct inode *inode, boo
static struct inode_security_struct *inode_security(struct inode *inode)
{
__inode_security_revalidate(inode, NULL, true);
- return inode->i_security;
+ return selinux_inode(inode);
}

static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
{
struct inode *inode = d_backing_inode(dentry);

- return inode->i_security;
+ return selinux_inode(inode);
}

/*
@@ -334,7 +334,7 @@ static struct inode_security_struct *backing_inode_security(struct dentry *dentr
struct inode *inode = d_backing_inode(dentry);

__inode_security_revalidate(inode, dentry, true);
- return inode->i_security;
+ return selinux_inode(inode);
}

static void inode_free_rcu(struct rcu_head *head)
@@ -347,7 +347,7 @@ static void inode_free_rcu(struct rcu_head *head)

static void inode_free_security(struct inode *inode)
{
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = selinux_inode(inode);
struct superblock_security_struct *sbsec = inode->i_sb->s_security;

/*
@@ -1502,7 +1502,7 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
{
struct superblock_security_struct *sbsec = NULL;
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = selinux_inode(inode);
u32 task_sid, sid = 0;
u16 sclass;
struct dentry *dentry;
@@ -1803,7 +1803,7 @@ static int inode_has_perm(const struct cred *cred,
return 0;

sid = cred_sid(cred);
- isec = inode->i_security;
+ isec = selinux_inode(inode);

return avc_has_perm(&selinux_state,
sid, isec->sid, isec->sclass, perms, adp);
@@ -3031,7 +3031,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,

/* Possibly defer initialization to selinux_complete_init. */
if (sbsec->flags & SE_SBINITIALIZED) {
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = selinux_inode(inode);
isec->sclass = inode_mode_to_security_class(inode->i_mode);
isec->sid = newsid;
isec->initialized = LABEL_INITIALIZED;
@@ -3131,7 +3131,7 @@ static noinline int audit_inode_permission(struct inode *inode,
unsigned flags)
{
struct common_audit_data ad;
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = selinux_inode(inode);
int rc;

ad.type = LSM_AUDIT_DATA_INODE;
@@ -4138,7 +4138,7 @@ static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
static void selinux_task_to_inode(struct task_struct *p,
struct inode *inode)
{
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = selinux_inode(inode);
u32 sid = task_sid(p);

spin_lock(&isec->lock);
@@ -6517,7 +6517,7 @@ static void selinux_release_secctx(char *secdata, u32 seclen)

static void selinux_inode_invalidate_secctx(struct inode *inode)
{
- struct inode_security_struct *isec = inode->i_security;
+ struct inode_security_struct *isec = selinux_inode(inode);

spin_lock(&isec->lock);
isec->initialized = LABEL_INVALID;
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index 2586fbc7e38c..3304a1ee58a4 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -172,4 +172,10 @@ static inline struct file_security_struct *selinux_file(const struct file *file)
return file->f_security;
}

+static inline struct inode_security_struct *selinux_inode(
+ const struct inode *inode)
+{
+ return inode->i_security;
+}
+
#endif /* _SELINUX_OBJSEC_H_ */
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index a0faf54c00b9..b1847b520772 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -1386,7 +1386,7 @@ static int sel_make_bools(struct selinux_fs_info *fsi)
if (len >= PAGE_SIZE)
goto out;

- isec = (struct inode_security_struct *)inode->i_security;
+ isec = selinux_inode(inode);
ret = security_genfs_sid(fsi->state, "selinuxfs", page,
SECCLASS_FILE, &sid);
if (ret) {
@@ -1949,7 +1949,7 @@ static int sel_fill_super(struct super_block *sb, void *data, int silent)
goto err;

inode->i_ino = ++fsi->last_ino;
- isec = (struct inode_security_struct *)inode->i_security;
+ isec = selinux_inode(inode);
isec->sid = SECINITSID_DEVNULL;
isec->sclass = SECCLASS_CHR_FILE;
isec->initialized = LABEL_INITIALIZED;
--
2.17.1