[PATCH 4/4] add task handling notifier: security keys

From: Jan Beulich
Date: Thu Dec 20 2007 - 08:13:37 EST


Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
---
arch/mips/kernel/kspd.c | 7 +++--
include/linux/key.h | 4 ---
kernel/sys.c | 8 ------
security/keys/process_keys.c | 55 ++++++++++++++++++++++++++-----------------
4 files changed, 39 insertions(+), 35 deletions(-)

--- 2.6.24-rc5-notify-task.orig/arch/mips/kernel/kspd.c
+++ 2.6.24-rc5-notify-task/arch/mips/kernel/kspd.c
@@ -25,6 +25,7 @@
#include <linux/workqueue.h>
#include <linux/errno.h>
#include <linux/list.h>
+#include <linux/notifier.h>

#include <asm/vpe.h>
#include <asm/rtlx.h>
@@ -177,8 +178,10 @@ static void sp_setfsuidgid( uid_t uid, g
current->fsuid = uid;
current->fsgid = gid;

- key_fsuid_changed(current);
- key_fsgid_changed(current);
+ blocking_notifier_call_chain(&task_notifier_list,
+ TASK_UID_CHANGE, current);
+ blocking_notifier_call_chain(&task_notifier_list,
+ TASK_GID_CHANGE, current);
}

/*
--- 2.6.24-rc5-notify-task.orig/include/linux/key.h
+++ 2.6.24-rc5-notify-task/include/linux/key.h
@@ -272,8 +272,6 @@ extern void exit_keys(struct task_struct
extern void exit_thread_group_keys(struct signal_struct *tg);
extern int suid_keys(struct task_struct *tsk);
extern int exec_keys(struct task_struct *tsk);
-extern void key_fsuid_changed(struct task_struct *tsk);
-extern void key_fsgid_changed(struct task_struct *tsk);
extern void key_init(void);

#define __install_session_keyring(tsk, keyring) \
@@ -302,8 +300,6 @@ extern void key_init(void);
#define exit_thread_group_keys(tg) do { } while(0)
#define suid_keys(t) do { } while(0)
#define exec_keys(t) do { } while(0)
-#define key_fsuid_changed(t) do { } while(0)
-#define key_fsgid_changed(t) do { } while(0)
#define key_init() do { } while(0)

/* Initial keyrings */
--- 2.6.24-rc5-notify-task.orig/kernel/sys.c
+++ 2.6.24-rc5-notify-task/kernel/sys.c
@@ -517,7 +517,6 @@ asmlinkage long sys_setregid(gid_t rgid,
current->fsgid = new_egid;
current->egid = new_egid;
current->gid = new_rgid;
- key_fsgid_changed(current);
blocking_notifier_call_chain(&task_notifier_list,
TASK_GID_CHANGE, current);

@@ -554,7 +553,6 @@ asmlinkage long sys_setgid(gid_t gid)
else
return -EPERM;

- key_fsgid_changed(current);
blocking_notifier_call_chain(&task_notifier_list,
TASK_GID_CHANGE, current);

@@ -644,7 +642,6 @@ asmlinkage long sys_setreuid(uid_t ruid,
current->suid = current->euid;
current->fsuid = current->euid;

- key_fsuid_changed(current);
blocking_notifier_call_chain(&task_notifier_list,
TASK_UID_CHANGE, current);

@@ -692,7 +689,6 @@ asmlinkage long sys_setuid(uid_t uid)
current->fsuid = current->euid = uid;
current->suid = new_suid;

- key_fsuid_changed(current);
blocking_notifier_call_chain(&task_notifier_list,
TASK_UID_CHANGE, current);

@@ -741,7 +737,6 @@ asmlinkage long sys_setresuid(uid_t ruid
if (suid != (uid_t) -1)
current->suid = suid;

- key_fsuid_changed(current);
blocking_notifier_call_chain(&task_notifier_list,
TASK_UID_CHANGE, current);

@@ -794,7 +789,6 @@ asmlinkage long sys_setresgid(gid_t rgid
if (sgid != (gid_t) -1)
current->sgid = sgid;

- key_fsgid_changed(current);
blocking_notifier_call_chain(&task_notifier_list,
TASK_GID_CHANGE, current);
return 0;
@@ -836,7 +830,6 @@ asmlinkage long sys_setfsuid(uid_t uid)
current->fsuid = uid;
}

- key_fsuid_changed(current);
blocking_notifier_call_chain(&task_notifier_list,
TASK_UID_CHANGE, current);

@@ -864,7 +857,6 @@ asmlinkage long sys_setfsgid(gid_t gid)
smp_wmb();
}
current->fsgid = gid;
- key_fsgid_changed(current);
blocking_notifier_call_chain(&task_notifier_list,
TASK_GID_CHANGE, current);
}
--- 2.6.24-rc5-notify-task.orig/security/keys/process_keys.c
+++ 2.6.24-rc5-notify-task/security/keys/process_keys.c
@@ -16,6 +16,7 @@
#include <linux/keyctl.h>
#include <linux/fs.h>
#include <linux/err.h>
+#include <linux/notifier.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>
#include "internal.h"
@@ -354,35 +355,47 @@ int suid_keys(struct task_struct *tsk)

} /* end suid_keys() */

-/*****************************************************************************/
-/*
- * the filesystem user ID changed
- */
-void key_fsuid_changed(struct task_struct *tsk)
-{
- /* update the ownership of the thread keyring */
- if (tsk->thread_keyring) {
+static int key_task_notifier(struct notifier_block *nb,
+ unsigned long action,
+ void *task)
+{
+ struct task_struct *tsk = task;
+
+ if (!tsk->thread_keyring)
+ return NOTIFY_DONE;
+
+ switch (action) {
+ case TASK_UID_CHANGE:
+ /* update the ownership of the thread keyring */
down_write(&tsk->thread_keyring->sem);
tsk->thread_keyring->uid = tsk->fsuid;
up_write(&tsk->thread_keyring->sem);
- }
-
-} /* end key_fsuid_changed() */
-
-/*****************************************************************************/
-/*
- * the filesystem group ID changed
- */
-void key_fsgid_changed(struct task_struct *tsk)
-{
- /* update the ownership of the thread keyring */
- if (tsk->thread_keyring) {
+ break;
+ case TASK_GID_CHANGE:
+ /* update the ownership of the thread keyring */
down_write(&tsk->thread_keyring->sem);
tsk->thread_keyring->gid = tsk->fsgid;
up_write(&tsk->thread_keyring->sem);
+ break;
}

-} /* end key_fsgid_changed() */
+ return NOTIFY_DONE;
+
+} /* end key_task_notifier() */
+
+static struct notifier_block key_task_notifier_block = {
+ .notifier_call = key_task_notifier
+};
+
+static int __init key_notifier_init(void)
+{
+ blocking_notifier_chain_register(&task_notifier_list,
+ &key_task_notifier_block);
+ return 0;
+
+} /* end key_notifier_init() */
+
+__initcall(key_notifier_init);

/*****************************************************************************/
/*


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