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Diffstat (limited to 'security/keys/keyctl.c')
-rw-r--r--security/keys/keyctl.c161
1 files changed, 139 insertions, 22 deletions
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 7f09fb897d2b..74c968524592 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -103,7 +103,7 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type,
}
/* find the target keyring (which must be writable) */
- keyring_ref = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+ keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref);
goto error3;
@@ -185,7 +185,8 @@ SYSCALL_DEFINE4(request_key, const char __user *, _type,
/* get the destination keyring if specified */
dest_ref = NULL;
if (destringid) {
- dest_ref = lookup_user_key(destringid, 1, 0, KEY_WRITE);
+ dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
+ KEY_WRITE);
if (IS_ERR(dest_ref)) {
ret = PTR_ERR(dest_ref);
goto error3;
@@ -233,9 +234,11 @@ SYSCALL_DEFINE4(request_key, const char __user *, _type,
long keyctl_get_keyring_ID(key_serial_t id, int create)
{
key_ref_t key_ref;
+ unsigned long lflags;
long ret;
- key_ref = lookup_user_key(id, create, 0, KEY_SEARCH);
+ lflags = create ? KEY_LOOKUP_CREATE : 0;
+ key_ref = lookup_user_key(id, lflags, KEY_SEARCH);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error;
@@ -309,7 +312,7 @@ long keyctl_update_key(key_serial_t id,
}
/* find the target key (which must be writable) */
- key_ref = lookup_user_key(id, 0, 0, KEY_WRITE);
+ key_ref = lookup_user_key(id, 0, KEY_WRITE);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error2;
@@ -337,10 +340,16 @@ long keyctl_revoke_key(key_serial_t id)
key_ref_t key_ref;
long ret;
- key_ref = lookup_user_key(id, 0, 0, KEY_WRITE);
+ key_ref = lookup_user_key(id, 0, KEY_WRITE);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
- goto error;
+ if (ret != -EACCES)
+ goto error;
+ key_ref = lookup_user_key(id, 0, KEY_SETATTR);
+ if (IS_ERR(key_ref)) {
+ ret = PTR_ERR(key_ref);
+ goto error;
+ }
}
key_revoke(key_ref_to_ptr(key_ref));
@@ -363,7 +372,7 @@ long keyctl_keyring_clear(key_serial_t ringid)
key_ref_t keyring_ref;
long ret;
- keyring_ref = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+ keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref);
goto error;
@@ -389,13 +398,13 @@ long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
key_ref_t keyring_ref, key_ref;
long ret;
- keyring_ref = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+ keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref);
goto error;
}
- key_ref = lookup_user_key(id, 1, 0, KEY_LINK);
+ key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_LINK);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error2;
@@ -423,13 +432,13 @@ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
key_ref_t keyring_ref, key_ref;
long ret;
- keyring_ref = lookup_user_key(ringid, 0, 0, KEY_WRITE);
+ keyring_ref = lookup_user_key(ringid, 0, KEY_WRITE);
if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref);
goto error;
}
- key_ref = lookup_user_key(id, 0, 0, 0);
+ key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error2;
@@ -465,7 +474,7 @@ long keyctl_describe_key(key_serial_t keyid,
char *tmpbuf;
long ret;
- key_ref = lookup_user_key(keyid, 0, 1, KEY_VIEW);
+ key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
if (IS_ERR(key_ref)) {
/* viewing a key under construction is permitted if we have the
* authorisation token handy */
@@ -474,7 +483,8 @@ long keyctl_describe_key(key_serial_t keyid,
if (!IS_ERR(instkey)) {
key_put(instkey);
key_ref = lookup_user_key(keyid,
- 0, 1, 0);
+ KEY_LOOKUP_PARTIAL,
+ 0);
if (!IS_ERR(key_ref))
goto okay;
}
@@ -558,7 +568,7 @@ long keyctl_keyring_search(key_serial_t ringid,
}
/* get the keyring at which to begin the search */
- keyring_ref = lookup_user_key(ringid, 0, 0, KEY_SEARCH);
+ keyring_ref = lookup_user_key(ringid, 0, KEY_SEARCH);
if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref);
goto error2;
@@ -567,7 +577,8 @@ long keyctl_keyring_search(key_serial_t ringid,
/* get the destination keyring if specified */
dest_ref = NULL;
if (destringid) {
- dest_ref = lookup_user_key(destringid, 1, 0, KEY_WRITE);
+ dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
+ KEY_WRITE);
if (IS_ERR(dest_ref)) {
ret = PTR_ERR(dest_ref);
goto error3;
@@ -637,7 +648,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
long ret;
/* find the key first */
- key_ref = lookup_user_key(keyid, 0, 0, 0);
+ key_ref = lookup_user_key(keyid, 0, 0);
if (IS_ERR(key_ref)) {
ret = -ENOKEY;
goto error;
@@ -700,7 +711,8 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid)
if (uid == (uid_t) -1 && gid == (gid_t) -1)
goto error;
- key_ref = lookup_user_key(id, 1, 1, KEY_SETATTR);
+ key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
+ KEY_SETATTR);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error;
@@ -805,7 +817,8 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
goto error;
- key_ref = lookup_user_key(id, 1, 1, KEY_SETATTR);
+ key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
+ KEY_SETATTR);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error;
@@ -847,7 +860,7 @@ static long get_instantiation_keyring(key_serial_t ringid,
/* if a specific keyring is nominated by ID, then use that */
if (ringid > 0) {
- dkref = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+ dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
if (IS_ERR(dkref))
return PTR_ERR(dkref);
*_dest_keyring = key_ref_to_ptr(dkref);
@@ -1083,7 +1096,8 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout)
time_t expiry;
long ret;
- key_ref = lookup_user_key(id, 1, 1, KEY_SETATTR);
+ key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
+ KEY_SETATTR);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error;
@@ -1101,6 +1115,7 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout)
}
key->expiry = expiry;
+ key_schedule_gc(key->expiry);
up_write(&key->sem);
key_put(key);
@@ -1170,7 +1185,7 @@ long keyctl_get_security(key_serial_t keyid,
char *context;
long ret;
- key_ref = lookup_user_key(keyid, 0, 1, KEY_VIEW);
+ key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
if (IS_ERR(key_ref)) {
if (PTR_ERR(key_ref) != -EACCES)
return PTR_ERR(key_ref);
@@ -1182,7 +1197,7 @@ long keyctl_get_security(key_serial_t keyid,
return PTR_ERR(key_ref);
key_put(instkey);
- key_ref = lookup_user_key(keyid, 0, 1, 0);
+ key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0);
if (IS_ERR(key_ref))
return PTR_ERR(key_ref);
}
@@ -1213,6 +1228,105 @@ long keyctl_get_security(key_serial_t keyid,
return ret;
}
+/*
+ * attempt to install the calling process's session keyring on the process's
+ * parent process
+ * - the keyring must exist and must grant us LINK permission
+ * - implements keyctl(KEYCTL_SESSION_TO_PARENT)
+ */
+long keyctl_session_to_parent(void)
+{
+ struct task_struct *me, *parent;
+ const struct cred *mycred, *pcred;
+ struct cred *cred, *oldcred;
+ key_ref_t keyring_r;
+ int ret;
+
+ keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK);
+ if (IS_ERR(keyring_r))
+ return PTR_ERR(keyring_r);
+
+ /* our parent is going to need a new cred struct, a new tgcred struct
+ * and new security data, so we allocate them here to prevent ENOMEM in
+ * our parent */
+ ret = -ENOMEM;
+ cred = cred_alloc_blank();
+ if (!cred)
+ goto error_keyring;
+
+ cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r);
+ keyring_r = NULL;
+
+ me = current;
+ write_lock_irq(&tasklist_lock);
+
+ parent = me->real_parent;
+ ret = -EPERM;
+
+ /* the parent mustn't be init and mustn't be a kernel thread */
+ if (parent->pid <= 1 || !parent->mm)
+ goto not_permitted;
+
+ /* the parent must be single threaded */
+ if (atomic_read(&parent->signal->count) != 1)
+ goto not_permitted;
+
+ /* the parent and the child must have different session keyrings or
+ * there's no point */
+ mycred = current_cred();
+ pcred = __task_cred(parent);
+ if (mycred == pcred ||
+ mycred->tgcred->session_keyring == pcred->tgcred->session_keyring)
+ goto already_same;
+
+ /* the parent must have the same effective ownership and mustn't be
+ * SUID/SGID */
+ if (pcred-> uid != mycred->euid ||
+ pcred->euid != mycred->euid ||
+ pcred->suid != mycred->euid ||
+ pcred-> gid != mycred->egid ||
+ pcred->egid != mycred->egid ||
+ pcred->sgid != mycred->egid)
+ goto not_permitted;
+
+ /* the keyrings must have the same UID */
+ if (pcred ->tgcred->session_keyring->uid != mycred->euid ||
+ mycred->tgcred->session_keyring->uid != mycred->euid)
+ goto not_permitted;
+
+ /* the LSM must permit the replacement of the parent's keyring with the
+ * keyring from this process */
+ ret = security_key_session_to_parent(mycred, pcred,
+ key_ref_to_ptr(keyring_r));
+ if (ret < 0)
+ goto not_permitted;
+
+ /* if there's an already pending keyring replacement, then we replace
+ * that */
+ oldcred = parent->replacement_session_keyring;
+
+ /* the replacement session keyring is applied just prior to userspace
+ * restarting */
+ parent->replacement_session_keyring = cred;
+ cred = NULL;
+ set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME);
+
+ write_unlock_irq(&tasklist_lock);
+ if (oldcred)
+ put_cred(oldcred);
+ return 0;
+
+already_same:
+ ret = 0;
+not_permitted:
+ put_cred(cred);
+ return ret;
+
+error_keyring:
+ key_ref_put(keyring_r);
+ return ret;
+}
+
/*****************************************************************************/
/*
* the key control system call
@@ -1298,6 +1412,9 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
(char __user *) arg3,
(size_t) arg4);
+ case KEYCTL_SESSION_TO_PARENT:
+ return keyctl_session_to_parent();
+
default:
return -EOPNOTSUPP;
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.