wallet: Disallow . and .. from wallet names

diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index d25c3912..49099bf7 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2942,17 +2942,34 @@ bool CWallet::EraseAddressReceiveRequest(WalletBatch& batch, const CTxDestinatio
 
 static util::Result<fs::path> GetWalletPath(const std::string& name)
 {
+    const fs::path name_path = fs::PathFromString(name);
+
+    // 'name' must be a normalized path, i.e. no . or .. except at the root
+    if (name_path != name_path.lexically_normal()) {
+        return util::Error{Untranslated("Wallet name given as a path must be normalized")};
+    }
+
+    // 'name' cannot begin with ./ or ../
+    if (!name_path.empty() && (*name_path.begin() == fs::PathFromString(".") || *name_path.begin() == fs::PathFromString(".."))) {
+        return util::Error{Untranslated("Wallet name given as a relative path cannot begin with ./ or ../, for wallets not in the walletdir, please use an absolute path.")};
+    }
+
+    // Disallow path at root
+    if (name_path.has_root_path() && name_path.root_path() == name_path) {
+        return util::Error{Untranslated("Wallet name cannot be the root path")};
+    }
+
     // Do some checking on wallet path. It should be either a:
     //
     // 1. Path where a directory can be created.
     // 2. Path to an existing directory.
     // 3. Path to a symlink to a directory.
     // 4. For backwards compatibility, the name of a data file in -walletdir.
-    const fs::path wallet_path = fsbridge::AbsPathJoin(GetWalletDir(), fs::PathFromString(name));
+    const fs::path wallet_path = fsbridge::AbsPathJoin(GetWalletDir(), name_path);
     fs::file_type path_type = fs::symlink_status(wallet_path).type();
     if (!(path_type == fs::file_type::not_found || path_type == fs::file_type::directory ||
           (path_type == fs::file_type::symlink && fs::is_directory(wallet_path)) ||
-          (path_type == fs::file_type::regular && fs::PathFromString(name).filename() == fs::PathFromString(name)))) {
+          (path_type == fs::file_type::regular && name_path.filename() == name_path))) {
         return util::Error{Untranslated(strprintf(
               "Invalid -wallet path '%s'. -wallet path should point to a directory where wallet.dat and "
               "database/log.?????????? files can be stored, a location where such a directory could be created, "
diff --git a/test/functional/wallet_migration.py b/test/functional/wallet_migration.py
index d4489eaa..e28cfd57 100755
--- a/test/functional/wallet_migration.py
+++ b/test/functional/wallet_migration.py
@@ -599,57 +599,6 @@ class WalletMigrationTest(BitcoinTestFramework):
 
         assert_equal(bals, wallet.getbalances())
 
-    def test_wallet_with_relative_path(self):
-        self.log.info("Test migration of a wallet that isn't loaded, specified by a relative path")
-
-        # Get the nearest common path of both nodes' wallet paths.
-        common_parent = os.path.commonpath([self.master_node.wallets_path, self.old_node.wallets_path])
-
-        # This test assumes that the relative path from each wallet directory to the common path is identical.
-        assert_equal(os.path.relpath(common_parent, start=self.master_node.wallets_path), os.path.relpath(common_parent, start=self.old_node.wallets_path))
-
-        wallet_name = "relative"
-        absolute_path = os.path.abspath(os.path.join(common_parent, wallet_name))
-        relative_name = os.path.relpath(absolute_path, start=self.master_node.wallets_path)
-
-        wallet = self.create_legacy_wallet(relative_name)
-        # listwalletdirs only returns wallets in the wallet directory
-        assert {"name": relative_name} not in wallet.listwalletdir()["wallets"]
-        assert relative_name in wallet.listwallets()
-
-        default = self.master_node.get_wallet_rpc(self.default_wallet_name)
-        addr = wallet.getnewaddress()
-        txid = default.sendtoaddress(addr, 1)
-        self.generate(self.master_node, 1)
-        bals = wallet.getbalances()
-        bals["mine"]["nonmempool"] = Decimal('0.0')
-
-        migrate_res, wallet = self.migrate_and_get_rpc(relative_name)
-
-        # Check that the wallet was migrated, knows the right txid, and has the right balance.
-        assert wallet.gettransaction(txid)
-        assert_equal(bals, wallet.getbalances())
-
-        # The migrated wallet should not be in the wallet dir, but should be in the list of wallets.
-        info = wallet.getwalletinfo()
-
-        walletdirlist = wallet.listwalletdir()
-        assert {"name": info["walletname"]} not in walletdirlist["wallets"]
-
-        walletlist = wallet.listwallets()
-        assert info["walletname"] in walletlist
-
-        # Check that old node can restore from the backup.
-        self.old_node.restorewallet("relative_restored", migrate_res['backup_path'])
-        wallet = self.old_node.get_wallet_rpc("relative_restored")
-        assert wallet.gettransaction(txid)
-        del bals["mine"]["nonmempool"]
-        assert_equal(bals, wallet.getbalances())
-
-        info = wallet.getwalletinfo()
-        assert_equal(info["descriptors"], False)
-        assert_equal(info["format"], "bdb")
-
     def test_wallet_with_path(self, wallet_path):
         self.log.info("Test migrating a wallet with the following path/name: %s", wallet_path)
         # the wallet data is actually inside of path/that/ends/
@@ -1122,53 +1071,6 @@ class WalletMigrationTest(BitcoinTestFramework):
         # Check the wallet we tried to migrate is still BDB
         self.assert_is_bdb("failed")
 
-    def test_failed_migration_cleanup_relative_path(self):
-        self.log.info("Test that a failed migration with a relative path is cleaned up")
-
-        # Get the nearest common path of both nodes' wallet paths.
-        common_parent = os.path.commonpath([self.master_node.wallets_path, self.old_node.wallets_path])
-
-        # This test assumes that the relative path from each wallet directory to the common path is identical.
-        assert_equal(os.path.relpath(common_parent, start=self.master_node.wallets_path), os.path.relpath(common_parent, start=self.old_node.wallets_path))
-
-        wallet_name = "relativefailure"
-        absolute_path = os.path.abspath(os.path.join(common_parent, wallet_name))
-        relative_name = os.path.relpath(absolute_path, start=self.master_node.wallets_path)
-
-        wallet = self.create_legacy_wallet(relative_name)
-
-        # Make a copy of the wallet with the solvables wallet name so that we are unable
-        # to create the solvables wallet when migrating, thus failing to migrate
-        wallet.unloadwallet()
-        solvables_path = os.path.join(common_parent, f"{wallet_name}_solvables")
-
-        shutil.copytree(self.old_node.wallets_path / relative_name, solvables_path)
-        original_shasum = sha256sum_file(os.path.join(solvables_path, "wallet.dat"))
-
-        self.old_node.loadwallet(relative_name)
-
-        # Add a multisig so that a solvables wallet is created
-        wallet.addmultisigaddress(2, [wallet.getnewaddress(), get_generate_key().pubkey])
-        wallet.importaddress(get_generate_key().p2pkh_addr)
-
-        self.old_node.unloadwallet(relative_name)
-        assert_raises_rpc_error(-4, "Failed to create database", self.master_node.migratewallet, relative_name)
-
-        assert all(wallet not in self.master_node.listwallets() for wallet in [f"{wallet_name}", f"{wallet_name}_watchonly", f"{wallet_name}_solvables"])
-
-        assert not (self.master_node.wallets_path / f"{wallet_name}_watchonly").exists()
-        # Since the file in failed_solvables is one that we put there, migration shouldn't touch it
-        assert os.path.exists(solvables_path)
-        new_shasum = sha256sum_file(os.path.join(solvables_path , "wallet.dat"))
-        assert_equal(original_shasum, new_shasum)
-
-        # Check the wallet we tried to migrate is still BDB
-        datfile = os.path.join(absolute_path, "wallet.dat")
-        with open(datfile, "rb") as f:
-            data = f.read(16)
-            _, _, magic = struct.unpack("QII", data)
-            assert_equal(magic, BTREE_MAGIC)
-
     def test_blank(self):
         self.log.info("Test that a blank wallet is migrated")
         wallet = self.create_legacy_wallet("blank", blank=True)
@@ -1687,13 +1589,11 @@ class WalletMigrationTest(BitcoinTestFramework):
         self.test_encrypted()
         self.test_nonexistent()
         self.test_unloaded_by_path()
-        self.test_wallet_with_relative_path()
-        self.test_wallet_with_path("path/to/mywallet/")
-        self.test_wallet_with_path("path/that/ends/in/..")
+        self.test_wallet_with_path("path/to/trailing/")
+        self.test_wallet_with_path("path/to/mywallet")
 
         migration_failure_cases = [
             "",
-            "../",
             os.path.abspath(self.master_node.datadir_path / "absolute_path"),
             "normallynamedwallet"
         ]
@@ -1708,7 +1608,6 @@ class WalletMigrationTest(BitcoinTestFramework):
         self.test_conflict_txs()
         self.test_hybrid_pubkey()
         self.test_failed_migration_cleanup()
-        self.test_failed_migration_cleanup_relative_path()
         self.test_avoidreuse()
         self.test_preserve_tx_extra_info()
         self.test_blank()
diff --git a/test/functional/wallet_multiwallet.py b/test/functional/wallet_multiwallet.py
index 5b9a23b5..6240126c 100755
--- a/test/functional/wallet_multiwallet.py
+++ b/test/functional/wallet_multiwallet.py
@@ -87,6 +87,8 @@ class MultiWalletTest(BitcoinTestFramework):
 
         assert_equal(node.listwalletdir(), {'wallets': [{'name': self.default_wallet_name, "warnings": []}]})
 
+        self.test_invalid_wallet_names()
+
         # check wallet.dat is created
         self.stop_nodes()
         assert_equal(os.path.isfile(wallet_dir(node, self.default_wallet_name, self.wallet_data_filename)), True)
@@ -458,6 +460,21 @@ class MultiWalletTest(BitcoinTestFramework):
         node.unloadwallet(wallet)
         self.nodes[1].loadwallet(wallet)
 
+    def test_invalid_wallet_names(self):
+        self.log.info("Test weird paths are not allowed as wallet names")
+        NON_NORMALIZED = ["bad/./path", "bad/../path", "/bad/./path", "/bad/../path", "../", "./", "./wallet", "../wallets/../wallets/wallet"]
+        for name in NON_NORMALIZED:
+            assert_raises_rpc_error(-4, "Wallet name given as a path must be normalized", self.nodes[0].createwallet, name)
+
+        INVALID_RELPATH = ["../wallets/wallet", "..", "."]
+        for name in INVALID_RELPATH:
+            assert_raises_rpc_error(-4, "Wallet name given as a relative path cannot begin with ./ or ../", self.nodes[0].createwallet, name)
+
+        INVALID_ROOT = ["/"]
+        if platform.system() == "Windows":
+            INVALID_ROOT.extend(["C:\\", "C:"])
+        for name in INVALID_ROOT:
+            assert_raises_rpc_error(-4, "Wallet name cannot be the root path", self.nodes[0].createwallet, name)
 
 if __name__ == '__main__':
     MultiWalletTest(__file__).main()