Jan Engelhardt
2006-05-01T13:49:59Z

[PATCH 3/4] task_post_setgid()

- Implement the task_post_setgid() LSM hook which is required by
MultiAdmin to switch between classes.
(task_post_setuid also switches between classes -- and already exists)

Signed-off-by: Jan Engelhardt <jengelh@gmx.de>

diff --fast -Ndpru -X dontdiff linux-2.6.17-rc3~/include/linux/security.h linux-2.6.17-rc3+/include/linux/security.h
--- linux-2.6.17-rc3~/include/linux/security.h 2006-05-01 09:57:13.112832000 +0200
+++ linux-2.6.17-rc3+/include/linux/security.h 2006-05-01 09:57:38.182832000 +0200
@@ -1320,6 +1320,7 @@ struct security_operations {
#endif /* CONFIG_KEYS */

int (*cap_extra)(int);
+ int (*task_post_setgid)(gid_t, gid_t, gid_t, int);
};

/* global variables */
@@ -2024,6 +2025,11 @@ static inline int security_cap_extra(int
return security_ops->cap_extra(cap);
}

+static inline int security_task_post_setgid(gid_t r, gid_t e, gid_t s, int t)
+{
+ return security_ops->task_post_setgid(r, e, s, t);
+}
+
/* prototypes */
extern int security_init (void);
extern int register_security (struct security_operations *ops);
@@ -2663,6 +2669,11 @@ static inline int security_cap_extra(int
return 1;
}

+static inline int security_task_post_setgid(gid_t r, gid_t e, gid_t s, int t)
+{
+ return 0;
+}
+
static inline struct dentry *securityfs_create_dir(const char *name,
struct dentry *parent)
{
diff --fast -Ndpru -X dontdiff linux-2.6.17-rc3~/kernel/sys.c linux-2.6.17-rc3+/kernel/sys.c
--- linux-2.6.17-rc3~/kernel/sys.c 2006-04-27 04:19:25.000000000 +0200
+++ linux-2.6.17-rc3+/kernel/sys.c 2006-05-01 09:57:38.192832000 +0200
@@ -836,7 +836,7 @@ asmlinkage long sys_setregid(gid_t rgid,
current->gid = new_rgid;
key_fsgid_changed(current);
proc_id_connector(current, PROC_EVENT_GID);
- return 0;
+ return security_task_post_setgid(old_rgid, old_egid, (gid_t)-1, LSM_SETID_RE);
}

/*
@@ -846,6 +846,7 @@ asmlinkage long sys_setregid(gid_t rgid,
*/
asmlinkage long sys_setgid(gid_t gid)
{
+ gid_t old_rgid = current->gid;
int old_egid = current->egid;
int retval;

@@ -876,7 +877,7 @@ asmlinkage long sys_setgid(gid_t gid)

key_fsgid_changed(current);
proc_id_connector(current, PROC_EVENT_GID);
- return 0;
+ return security_task_post_setgid(old_rgid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
}

static int set_user(uid_t new_ruid, int dumpclear)
@@ -1083,6 +1084,8 @@ asmlinkage long sys_getresuid(uid_t __us
*/
asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
{
+ gid_t old_rgid = current->gid, old_egid = current->egid,
+ old_sgid = current->sgid;
int retval;

retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
@@ -1116,7 +1119,7 @@ asmlinkage long sys_setresgid(gid_t rgid

key_fsgid_changed(current);
proc_id_connector(current, PROC_EVENT_GID);
- return 0;
+ return security_task_post_setgid(old_rgid, old_egid, old_sgid, LSM_SETID_RES);
}

asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
@@ -1189,6 +1192,7 @@ asmlinkage long sys_setfsgid(gid_t gid)
key_fsgid_changed(current);
proc_id_connector(current, PROC_EVENT_GID);
}
+ security_task_post_setgid(old_fsgid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS);
return old_fsgid;
}

diff --fast -Ndpru -X dontdiff linux-2.6.17-rc3~/security/dummy.c linux-2.6.17-rc3+/security/dummy.c
--- linux-2.6.17-rc3~/security/dummy.c 2006-05-01 09:57:13.112832000 +0200
+++ linux-2.6.17-rc3+/security/dummy.c 2006-05-01 09:57:38.192832000 +0200
@@ -682,6 +682,11 @@ static int dummy_cap_extra(int cap)
return 1; /* allow */
}

+static int dummy_task_post_setgid(gid_t r, gid_t e, gid_t s, int t)
+{
+ return 0;
+}
+
#ifdef CONFIG_SECURITY_NETWORK
static int dummy_unix_stream_connect (struct socket *sock,
struct socket *other,
@@ -1046,5 +1051,6 @@ void security_fixup_ops (struct security
#endif /* CONFIG_KEYS */

set_to_dummy_if_null(ops, cap_extra);
+ set_to_dummy_if_null(ops, task_post_setgid);
}

#<<eof>>

Jan Engelhardt
--