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authorMichael LeMay <mdlemay@epoch.ncsc.mil>2006-06-26 00:24:57 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 09:58:18 -0700
commit4eb582cf1fbd7b9e5f466e3718a59c957e75254e (patch)
tree4387e460a50efa8d46a54526d0cf0959c0e3b428 /security
parent06ec7be557a1259611d6093a00463c42650dc71a (diff)
[PATCH] keys: add a way to store the appropriate context for newly-created keys
Add a /proc/<pid>/attr/keycreate entry that stores the appropriate context for newly-created keys. Modify the selinux_key_alloc hook to make use of the new entry. Update the flask headers to include a new "setkeycreate" permission for processes. Update the flask headers to include a new "create" permission for keys. Use the create permission to restrict which SIDs each task can assign to newly-created keys. Add a new parameter to the security hook "security_key_alloc" to indicate whether it is being invoked by the kernel, or from userspace. If it is being invoked by the kernel, the security hook should never fail. Update the documentation to reflect these changes. Signed-off-by: Michael LeMay <mdlemay@epoch.ncsc.mil> Signed-off-by: James Morris <jmorris@namei.org> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'security')
-rw-r--r--security/selinux/hooks.c35
-rw-r--r--security/selinux/include/av_perm_to_string.h2
-rw-r--r--security/selinux/include/av_permissions.h3
-rw-r--r--security/selinux/include/objsec.h1
4 files changed, 34 insertions, 7 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 13384fef0d6..0d8b27513bd 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1099,6 +1099,17 @@ static int may_create(struct inode *dir,
FILESYSTEM__ASSOCIATE, &ad);
}
+/* Check whether a task can create a key. */
+static int may_create_key(u32 ksid,
+ struct task_struct *ctx)
+{
+ struct task_security_struct *tsec;
+
+ tsec = ctx->security;
+
+ return avc_has_perm(tsec->sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
+}
+
#define MAY_LINK 0
#define MAY_UNLINK 1
#define MAY_RMDIR 2
@@ -4150,6 +4161,8 @@ static int selinux_getprocattr(struct task_struct *p,
sid = tsec->exec_sid;
else if (!strcmp(name, "fscreate"))
sid = tsec->create_sid;
+ else if (!strcmp(name, "keycreate"))
+ sid = tsec->keycreate_sid;
else
return -EINVAL;
@@ -4182,6 +4195,8 @@ static int selinux_setprocattr(struct task_struct *p,
error = task_has_perm(current, p, PROCESS__SETEXEC);
else if (!strcmp(name, "fscreate"))
error = task_has_perm(current, p, PROCESS__SETFSCREATE);
+ else if (!strcmp(name, "keycreate"))
+ error = task_has_perm(current, p, PROCESS__SETKEYCREATE);
else if (!strcmp(name, "current"))
error = task_has_perm(current, p, PROCESS__SETCURRENT);
else
@@ -4211,7 +4226,12 @@ static int selinux_setprocattr(struct task_struct *p,
tsec->exec_sid = sid;
else if (!strcmp(name, "fscreate"))
tsec->create_sid = sid;
- else if (!strcmp(name, "current")) {
+ else if (!strcmp(name, "keycreate")) {
+ error = may_create_key(sid, p);
+ if (error)
+ return error;
+ tsec->keycreate_sid = sid;
+ } else if (!strcmp(name, "current")) {
struct av_decision avd;
if (sid == 0)
@@ -4275,7 +4295,10 @@ static int selinux_key_alloc(struct key *k, struct task_struct *tsk,
return -ENOMEM;
ksec->obj = k;
- ksec->sid = tsec->sid;
+ if (tsec->keycreate_sid)
+ ksec->sid = tsec->keycreate_sid;
+ else
+ ksec->sid = tsec->sid;
k->security = ksec;
return 0;
@@ -4514,10 +4537,10 @@ static __init int selinux_init(void)
#ifdef CONFIG_KEYS
/* Add security information to initial keyrings */
- security_key_alloc(&root_user_keyring, current,
- KEY_ALLOC_NOT_IN_QUOTA);
- security_key_alloc(&root_session_keyring, current,
- KEY_ALLOC_NOT_IN_QUOTA);
+ selinux_key_alloc(&root_user_keyring, current,
+ KEY_ALLOC_NOT_IN_QUOTA);
+ selinux_key_alloc(&root_session_keyring, current,
+ KEY_ALLOC_NOT_IN_QUOTA);
#endif
return 0;
diff --git a/security/selinux/include/av_perm_to_string.h b/security/selinux/include/av_perm_to_string.h
index bc020bde6c8..e777578ccd9 100644
--- a/security/selinux/include/av_perm_to_string.h
+++ b/security/selinux/include/av_perm_to_string.h
@@ -72,6 +72,7 @@
S_(SECCLASS_PROCESS, PROCESS__EXECMEM, "execmem")
S_(SECCLASS_PROCESS, PROCESS__EXECSTACK, "execstack")
S_(SECCLASS_PROCESS, PROCESS__EXECHEAP, "execheap")
+ S_(SECCLASS_PROCESS, PROCESS__SETKEYCREATE, "setkeycreate")
S_(SECCLASS_MSGQ, MSGQ__ENQUEUE, "enqueue")
S_(SECCLASS_MSG, MSG__SEND, "send")
S_(SECCLASS_MSG, MSG__RECEIVE, "receive")
@@ -248,3 +249,4 @@
S_(SECCLASS_KEY, KEY__SEARCH, "search")
S_(SECCLASS_KEY, KEY__LINK, "link")
S_(SECCLASS_KEY, KEY__SETATTR, "setattr")
+ S_(SECCLASS_KEY, KEY__CREATE, "create")
diff --git a/security/selinux/include/av_permissions.h b/security/selinux/include/av_permissions.h
index 1205227a3a3..1e1678023b6 100644
--- a/security/selinux/include/av_permissions.h
+++ b/security/selinux/include/av_permissions.h
@@ -467,6 +467,7 @@
#define PROCESS__EXECMEM 0x02000000UL
#define PROCESS__EXECSTACK 0x04000000UL
#define PROCESS__EXECHEAP 0x08000000UL
+#define PROCESS__SETKEYCREATE 0x10000000UL
#define IPC__CREATE 0x00000001UL
#define IPC__DESTROY 0x00000002UL
@@ -966,4 +967,4 @@
#define KEY__SEARCH 0x00000008UL
#define KEY__LINK 0x00000010UL
#define KEY__SETATTR 0x00000020UL
-
+#define KEY__CREATE 0x00000040UL
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index 8f5547ad185..191b3e4484c 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -32,6 +32,7 @@ struct task_security_struct {
u32 sid; /* current SID */
u32 exec_sid; /* exec SID */
u32 create_sid; /* fscreate SID */
+ u32 keycreate_sid; /* keycreate SID */
u32 ptrace_sid; /* SID of ptrace parent */
};