[patch 15/15] lsm stacking v0.3: stacking for digsig
From: serue
Date: Wed Jul 27 2005 - 14:16:42 EST
Support stacking in digsig. This patch is on top of the cvs version from
www.sf.net/projects/disec.
[Jul 16] Update to support dynamic unloading by freeing
object->security data at unload.
Signed-off-by: Serge Hallyn <serue@xxxxxxxxxx>
--
digsig.c | 142 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------
1 files changed, 128 insertions(+), 14 deletions(-)
--- digsig/digsig.c 2005-07-06 08:41:38.000000000 -0500
+++ digsig-patched/digsig.c 2005-07-25 16:08:36.000000000 -0500
@@ -33,6 +33,7 @@
#include <linux/fs.h>
#include <asm/uaccess.h>
#include <linux/security.h>
+#include <linux/security-stack.h>
#include <linux/dcache.h>
#include <linux/kobject.h>
#include <linux/mman.h>
@@ -47,6 +48,8 @@
#include "gnupg/mpi/mpi.h"
#include "gnupg/cipher/rsa-verify.h"
+#define DIGSIG_LSM_ID 0x5AA8
+
#ifdef DIGSIG_DEBUG
#define DIGSIG_MODE 0 /*permissive mode */
#define DIGSIG_BENCH 1
@@ -55,11 +58,11 @@
#define DIGSIG_BENCH 0
#endif
-#define get_inode_security(ino) ((unsigned long)(ino->i_security))
-#define set_inode_security(ino,val) (ino->i_security = (void *)val)
-
-#define get_file_security(file) ((unsigned long)(file->f_security))
-#define set_file_security(file,val) (file->f_security = (void *)val)
+struct digsig_ksec {
+ struct security_list lsm_list;
+ struct list_head chain;
+ unsigned count;
+};
unsigned long int total_jiffies = 0;
@@ -82,6 +85,73 @@ int dsi_cache_buckets = 128;
module_param(dsi_cache_buckets, int, 0);
MODULE_PARM_DESC(dsi_cache_buckets, "Number of cache buckets for signatures validations.\n");
+LIST_HEAD(digsig_del_chain);
+DEFINE_SPINLOCK(digsig_chain_lock);
+
+static int get_file_security(struct file *file)
+{
+ struct digsig_ksec *ksec;
+
+ ksec = security_get_value_type(&file->f_security, DIGSIG_LSM_ID,
+ struct digsig_ksec);
+ if (!ksec)
+ return 0;
+ return ksec->count;
+}
+
+static int set_file_security(struct file *file, int v)
+{
+ struct digsig_ksec *ksec;
+
+ ksec = security_get_value_type(&file->f_security, DIGSIG_LSM_ID,
+ struct digsig_ksec);
+ if (!ksec) {
+ ksec = kmalloc(sizeof(struct digsig_ksec), GFP_KERNEL);
+ if (!ksec)
+ return -ENOMEM;
+ INIT_LIST_HEAD(&ksec->chain);
+ spin_lock(&digsig_chain_lock);
+ list_add_rcu(&ksec->chain, &digsig_del_chain);
+ spin_unlock(&digsig_chain_lock);
+ security_add_value_type(&file->f_security, DIGSIG_LSM_ID,
+ ksec);
+ }
+ ksec->count = v;
+ return 0;
+}
+
+
+static int get_inode_security(struct inode *inode)
+{
+ struct digsig_ksec *ksec;
+
+ ksec = security_get_value_type(&inode->i_security, DIGSIG_LSM_ID,
+ struct digsig_ksec);
+ if (!ksec)
+ return 0;
+ return ksec->count;
+}
+
+static int set_inode_security(struct inode *inode, int v)
+{
+ struct digsig_ksec *ksec;
+
+ ksec = security_get_value_type(&inode->i_security, DIGSIG_LSM_ID,
+ struct digsig_ksec);
+ if (!ksec) {
+ ksec = kmalloc(sizeof(struct digsig_ksec), GFP_KERNEL);
+ if (!ksec)
+ return -ENOMEM;
+ INIT_LIST_HEAD(&ksec->chain);
+ spin_lock(&digsig_chain_lock);
+ list_add(&ksec->chain, &digsig_del_chain);
+ spin_unlock(&digsig_chain_lock);
+ security_add_value_type(&inode->i_security, DIGSIG_LSM_ID,
+ ksec);
+ }
+ ksec->count = v;
+ return 0;
+}
/******************************************************************************
Description :
@@ -342,18 +412,22 @@ static int digsig_deny_write_access(stru
{
struct inode *inode = file->f_dentry->d_inode;
unsigned long isec;
+ int err;
spin_lock(&inode->i_lock);
isec = get_inode_security(inode);
if (atomic_read(&inode->i_writecount) > 0) {
- spin_unlock(&inode->i_lock);
- return -ETXTBSY;
+ err = -ETXTBSY;
+ goto out;
}
set_inode_security(inode, (isec+1));
- set_file_security(file, 1);
- spin_unlock(&inode->i_lock);
+ err = set_file_security(file, 1);
+ if (err)
+ set_inode_security(inode, (isec));
- return 0;
+out:
+ spin_unlock(&inode->i_lock);
+ return err;
}
/*
@@ -379,9 +453,17 @@ static void digsig_allow_write_access(st
*/
static void digsig_file_free_security(struct file *file)
{
- if (file->f_security) {
- digsig_allow_write_access(file);
- }
+ struct digsig_ksec *ksec;
+
+ ksec = security_get_value_type(&file->f_security, DIGSIG_LSM_ID,
+ struct digsig_ksec);
+ if (!ksec)
+ return;
+
+ spin_lock(&digsig_chain_lock);
+ list_del(&ksec->chain);
+ spin_unlock(&digsig_chain_lock);
+ kfree(ksec);
}
/**
@@ -530,7 +612,7 @@ static inline int is_unprotected_file(st
__FUNCTION__, file->f_dentry->d_name.name, exec_time); \
}
-static int digsig_file_mmap(struct file * file, unsigned long prot, unsigned long flags)
+static int digsig_file_mmap(struct file * file, unsigned long reqprot, unsigned long prot, unsigned long flags)
{
struct elf64_hdr *elf64_ex;
struct elf32_hdr *elf32_ex;
@@ -668,8 +750,20 @@ static int digsig_file_mmap(struct file
static void digsig_inode_free_security(struct inode *inode)
{
+ struct digsig_ksec *ksec;
+
if (is_cached_signature(inode))
remove_signature(inode);
+
+ ksec = security_del_value_type(&inode->i_security, DIGSIG_LSM_ID,
+ struct digsig_ksec);
+ if (!ksec)
+ return;
+
+ spin_lock(&digsig_chain_lock);
+ list_del(&ksec->chain);
+ spin_unlock(&digsig_chain_lock);
+ kfree(ksec);
}
static struct security_operations digsig_security_ops = {
@@ -715,6 +809,25 @@ out:
return ret;
}
+static void digsig_free_secchain(void)
+{
+ struct digsig_ksec *ksec, *n;
+
+ list_for_each_entry_safe(ksec, n, &digsig_del_chain, chain) {
+ printk(KERN_NOTICE "free_ichain unlinking %u, %d, %lu\n",
+ ksec->count, ksec->lsm_list.security_id,
+ (unsigned long)ksec->lsm_list.list.pprev);
+ security_unlink_value(&ksec->lsm_list.list);
+ }
+
+ synchronize_rcu();
+ list_for_each_entry_safe(ksec, n, &digsig_del_chain, chain) {
+ printk(KERN_NOTICE "free_ichain freeing 1\n");
+ list_del(&ksec->chain);
+ kfree(ksec);
+ }
+}
+
static void __exit digsig_exit_module(void)
{
DSM_PRINT (DEBUG_INIT, "Deinitializing module\n");
@@ -734,6 +847,7 @@ static void __exit digsig_exit_module(vo
digsig_cleanup_sysfs();
digsig_cleanup_revocation();
digsig_cache_cleanup();
+ digsig_free_secchain();
mpi_free(digsig_public_key[0]);
mpi_free(digsig_public_key[1]);
}
-
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