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Diffstat (limited to 'security/smack/smack_lsm.c')
-rw-r--r--security/smack/smack_lsm.c74
1 files changed, 50 insertions, 24 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 7e19afe0e738..05dc4da2e25f 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3,12 +3,14 @@
*
* This file contains the smack hook function implementations.
*
- * Author:
+ * Authors:
* Casey Schaufler <casey@schaufler-ca.com>
+ * Jarkko Sakkinen <ext-jarkko.2.sakkinen@nokia.com>
*
* Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
* Paul Moore <paul.moore@hp.com>
+ * Copyright (C) 2010 Nokia Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2,
@@ -35,6 +37,9 @@
#define task_security(task) (task_cred_xxx((task), security))
+#define TRANS_TRUE "TRUE"
+#define TRANS_TRUE_SIZE 4
+
/**
* smk_fetch - Fetch the smack label from a file.
* @ip: a pointer to the inode
@@ -468,6 +473,8 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
char **name, void **value, size_t *len)
{
char *isp = smk_of_inode(inode);
+ char *dsp = smk_of_inode(dir);
+ u32 may;
if (name) {
*name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
@@ -476,6 +483,16 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
}
if (value) {
+ may = smk_access_entry(smk_of_current(), dsp);
+
+ /*
+ * If the access rule allows transmutation and
+ * the directory requests transmutation then
+ * by all means transmute.
+ */
+ if (((may & MAY_TRANSMUTE) != 0) && smk_inode_transmutable(dir))
+ isp = dsp;
+
*value = kstrdup(isp, GFP_KERNEL);
if (*value == NULL)
return -ENOMEM;
@@ -709,6 +726,12 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name,
if (size == 0 || size >= SMK_LABELLEN ||
smk_import(value, size) == NULL)
rc = -EINVAL;
+ } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
+ if (!capable(CAP_MAC_ADMIN))
+ rc = -EPERM;
+ if (size != TRANS_TRUE_SIZE ||
+ strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
+ rc = -EINVAL;
} else
rc = cap_inode_setxattr(dentry, name, value, size, flags);
@@ -735,35 +758,23 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name,
static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
- struct inode_smack *isp;
char *nsp;
-
- /*
- * Not SMACK or SMACKEXEC
- */
- if (strcmp(name, XATTR_NAME_SMACK) &&
- strcmp(name, XATTR_NAME_SMACKEXEC))
- return;
-
- isp = dentry->d_inode->i_security;
-
- /*
- * No locking is done here. This is a pointer
- * assignment.
- */
- nsp = smk_import(value, size);
+ struct inode_smack *isp = dentry->d_inode->i_security;
if (strcmp(name, XATTR_NAME_SMACK) == 0) {
+ nsp = smk_import(value, size);
if (nsp != NULL)
isp->smk_inode = nsp;
else
isp->smk_inode = smack_known_invalid.smk_known;
- } else {
+ } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
+ nsp = smk_import(value, size);
if (nsp != NULL)
isp->smk_task = nsp;
else
isp->smk_task = smack_known_invalid.smk_known;
- }
+ } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
+ isp->smk_flags |= SMK_INODE_TRANSMUTE;
return;
}
@@ -803,7 +814,8 @@ static int smack_inode_removexattr(struct dentry *dentry, const char *name)
if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
- strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
+ strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
+ strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
if (!capable(CAP_MAC_ADMIN))
rc = -EPERM;
} else
@@ -2274,6 +2286,8 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
char *csp = smk_of_current();
char *fetched;
char *final;
+ char trattr[TRANS_TRUE_SIZE];
+ int transflag = 0;
struct dentry *dp;
if (inode == NULL)
@@ -2392,10 +2406,19 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
*/
dp = dget(opt_dentry);
fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp);
- if (fetched != NULL)
+ if (fetched != NULL) {
final = fetched;
- isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode,
- dp);
+ if (S_ISDIR(inode->i_mode)) {
+ trattr[0] = '\0';
+ inode->i_op->getxattr(dp,
+ XATTR_NAME_SMACKTRANSMUTE,
+ trattr, TRANS_TRUE_SIZE);
+ if (strncmp(trattr, TRANS_TRUE,
+ TRANS_TRUE_SIZE) == 0)
+ transflag = SMK_INODE_TRANSMUTE;
+ }
+ }
+ isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
dput(dp);
break;
@@ -2406,7 +2429,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
else
isp->smk_inode = final;
- isp->smk_flags |= SMK_INODE_INSTANT;
+ isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
unlockandout:
mutex_unlock(&isp->smk_lock);
@@ -2456,6 +2479,7 @@ static int smack_setprocattr(struct task_struct *p, char *name,
void *value, size_t size)
{
struct task_smack *tsp;
+ struct task_smack *oldtsp;
struct cred *new;
char *newsmack;
@@ -2485,6 +2509,7 @@ static int smack_setprocattr(struct task_struct *p, char *name,
if (newsmack == smack_known_web.smk_known)
return -EPERM;
+ oldtsp = p->cred->security;
new = prepare_creds();
if (new == NULL)
return -ENOMEM;
@@ -2494,6 +2519,7 @@ static int smack_setprocattr(struct task_struct *p, char *name,
return -ENOMEM;
}
tsp->smk_task = newsmack;
+ tsp->smk_forked = oldtsp->smk_forked;
new->security = tsp;
commit_creds(new);
return size;