Commit d47be3df authored by David Quigley's avatar David Quigley Committed by Trond Myklebust

Security: Add hook to calculate context based on a negative dentry.

There is a time where we need to calculate a context without the
inode having been created yet. To do this we take the negative dentry and
calculate a context based on the process and the parent directory contexts.
Acked-by: default avatarEric Paris <eparis@redhat.com>
Acked-by: default avatarJames Morris <james.l.morris@oracle.com>
Signed-off-by: default avatarMatthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: default avatarMiguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: default avatarPhua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: default avatarKhin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: default avatarSteve Dickson <steved@redhat.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 4488cc96
......@@ -26,6 +26,7 @@
#include <linux/capability.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/string.h>
struct linux_binprm;
struct cred;
......@@ -306,6 +307,15 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* Parse a string of security data filling in the opts structure
* @options string containing all mount options known by the LSM
* @opts binary data structure usable by the LSM
* @dentry_init_security:
* Compute a context for a dentry as the inode is not yet available
* since NFSv4 has no label backed by an EA anyway.
* @dentry dentry to use in calculating the context.
* @mode mode used to determine resource type.
* @name name of the last path component used to create file
* @ctx pointer to place the pointer to the resulting context in.
* @ctxlen point to place the length of the resulting context.
*
*
* Security hooks for inode operations.
*
......@@ -1443,6 +1453,10 @@ struct security_operations {
int (*sb_clone_mnt_opts) (const struct super_block *oldsb,
struct super_block *newsb);
int (*sb_parse_opts_str) (char *options, struct security_mnt_opts *opts);
int (*dentry_init_security) (struct dentry *dentry, int mode,
struct qstr *name, void **ctx,
u32 *ctxlen);
#ifdef CONFIG_SECURITY_PATH
int (*path_unlink) (struct path *dir, struct dentry *dentry);
......@@ -1729,6 +1743,9 @@ int security_sb_set_mnt_opts(struct super_block *sb, struct security_mnt_opts *o
int security_sb_clone_mnt_opts(const struct super_block *oldsb,
struct super_block *newsb);
int security_sb_parse_opts_str(char *options, struct security_mnt_opts *opts);
int security_dentry_init_security(struct dentry *dentry, int mode,
struct qstr *name, void **ctx,
u32 *ctxlen);
int security_inode_alloc(struct inode *inode);
void security_inode_free(struct inode *inode);
......@@ -2035,6 +2052,16 @@ static inline int security_inode_alloc(struct inode *inode)
static inline void security_inode_free(struct inode *inode)
{ }
static inline int security_dentry_init_security(struct dentry *dentry,
int mode,
struct qstr *name,
void **ctx,
u32 *ctxlen)
{
return -EOPNOTSUPP;
}
static inline int security_inode_init_security(struct inode *inode,
struct inode *dir,
const struct qstr *qstr,
......
......@@ -109,6 +109,13 @@ static int cap_sb_parse_opts_str(char *options, struct security_mnt_opts *opts)
return 0;
}
static int cap_dentry_init_security(struct dentry *dentry, int mode,
struct qstr *name, void **ctx,
u32 *ctxlen)
{
return 0;
}
static int cap_inode_alloc_security(struct inode *inode)
{
return 0;
......@@ -931,6 +938,7 @@ void __init security_fixup_ops(struct security_operations *ops)
set_to_cap_if_null(ops, sb_set_mnt_opts);
set_to_cap_if_null(ops, sb_clone_mnt_opts);
set_to_cap_if_null(ops, sb_parse_opts_str);
set_to_cap_if_null(ops, dentry_init_security);
set_to_cap_if_null(ops, inode_alloc_security);
set_to_cap_if_null(ops, inode_free_security);
set_to_cap_if_null(ops, inode_init_security);
......
......@@ -12,6 +12,7 @@
*/
#include <linux/capability.h>
#include <linux/dcache.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
......@@ -324,6 +325,15 @@ void security_inode_free(struct inode *inode)
security_ops->inode_free_security(inode);
}
int security_dentry_init_security(struct dentry *dentry, int mode,
struct qstr *name, void **ctx,
u32 *ctxlen)
{
return security_ops->dentry_init_security(dentry, mode, name,
ctx, ctxlen);
}
EXPORT_SYMBOL(security_dentry_init_security);
int security_inode_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr,
const initxattrs initxattrs, void *fs_data)
......
......@@ -2515,6 +2515,40 @@ static void selinux_inode_free_security(struct inode *inode)
inode_free_security(inode);
}
static int selinux_dentry_init_security(struct dentry *dentry, int mode,
struct qstr *name, void **ctx,
u32 *ctxlen)
{
const struct cred *cred = current_cred();
struct task_security_struct *tsec;
struct inode_security_struct *dsec;
struct superblock_security_struct *sbsec;
struct inode *dir = dentry->d_parent->d_inode;
u32 newsid;
int rc;
tsec = cred->security;
dsec = dir->i_security;
sbsec = dir->i_sb->s_security;
if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
newsid = tsec->create_sid;
} else {
rc = security_transition_sid(tsec->sid, dsec->sid,
inode_mode_to_security_class(mode),
name,
&newsid);
if (rc) {
printk(KERN_WARNING
"%s: security_transition_sid failed, rc=%d\n",
__func__, -rc);
return rc;
}
}
return security_sid_to_context(newsid, (char **)ctx, ctxlen);
}
static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr, char **name,
void **value, size_t *len)
......@@ -5562,6 +5596,7 @@ static struct security_operations selinux_ops = {
.sb_clone_mnt_opts = selinux_sb_clone_mnt_opts,
.sb_parse_opts_str = selinux_parse_opts_str,
.dentry_init_security = selinux_dentry_init_security,
.inode_alloc_security = selinux_inode_alloc_security,
.inode_free_security = selinux_inode_free_security,
......
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