tar: Check empty dir name handling

Make sure that empty wide character names do not lead to out of boundary
accesses.

Reported by shura-turtle.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>

diff --git a/Makefile.am b/Makefile.am
index 5604df7d59c3455556435c972f7ffc744ae4d157..abcdf47196dc83994e92d54026e60e2995df9124 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -682,6 +682,7 @@ libarchive_test_SOURCES= \
        libarchive/test/test_write_format_raw_b64.c \
        libarchive/test/test_write_format_shar_empty.c \
        libarchive/test/test_write_format_tar.c \
+       libarchive/test/test_write_format_tar_empty_dirname.c \
        libarchive/test/test_write_format_tar_empty.c \
        libarchive/test/test_write_format_tar_sparse.c \
        libarchive/test/test_write_format_tar_ustar.c \

diff --git a/libarchive/test/CMakeLists.txt b/libarchive/test/CMakeLists.txt
index ef228080e93d6fcf484b3cbf7c30d691b08d014a..c75712b095a88ad0bd29b47555d72339f41cc606 100644 (file)
--- a/libarchive/test/CMakeLists.txt
+++ b/libarchive/test/CMakeLists.txt
@@ -314,6 +314,7 @@ IF(ENABLE_TEST)
     test_write_format_raw_b64.c
     test_write_format_shar_empty.c
     test_write_format_tar.c
+    test_write_format_tar_empty_dirname.c
     test_write_format_tar_empty.c
     test_write_format_tar_sparse.c
     test_write_format_tar_ustar.c

diff --git a/libarchive/test/test_write_format_tar_empty_dirname.c b/libarchive/test/test_write_format_tar_empty_dirname.c
new file mode 100644 (file)
index 0000000..7536078
--- /dev/null
+++ b/libarchive/test/test_write_format_tar_empty_dirname.c
@@ -0,0 +1,82 @@
+/*-
+ * Copyright (c) 2026 Tobias Stoeckmann
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "test.h"
+
+static void
+test_format(int (*set_format)(struct archive *))
+{
+       struct archive *a;
+       struct archive_entry *entry;
+       char buff[2048];
+       size_t used;
+
+       /* Create a new archive in memory. */
+       assert((a = archive_write_new()) != NULL);
+       assertA(0 == set_format(a));
+       assertA(0 == archive_write_add_filter_none(a));
+       assertA(0 == archive_write_set_bytes_per_block(a, 512));
+       assertA(0 == archive_write_set_bytes_in_last_block(a, 512));
+       assertA(0 == archive_write_open_memory(a, buff, sizeof(buff), &used));
+
+       /* Write directory with empty wide character name */
+       assert((entry = archive_entry_new()) != NULL);
+       archive_entry_copy_pathname_w(entry, L"");
+       archive_entry_set_mode(entry, S_IFDIR | 0755);
+       archive_entry_set_uid(entry, 0);
+       archive_entry_set_gid(entry, 0);
+       assertEqualIntA(a, ARCHIVE_OK, archive_write_header(a, entry));
+
+       /* Close out the archive. */
+       archive_entry_free(entry);
+       assertEqualIntA(a, ARCHIVE_OK, archive_write_close(a));
+       assertEqualInt(ARCHIVE_OK, archive_write_free(a));
+
+       /*
+        * Now, read the data back.
+        */
+       assert((a = archive_read_new()) != NULL);
+       assertEqualIntA(a, ARCHIVE_OK, archive_read_support_format_all(a));
+       assertEqualIntA(a, ARCHIVE_OK, archive_read_support_filter_all(a));
+       assertEqualIntA(a, ARCHIVE_OK,
+           archive_read_open_memory(a, buff, used));
+       assertEqualIntA(a, ARCHIVE_OK,
+           archive_read_next_header(a, &entry));
+       assertEqualString("", archive_entry_pathname(entry));
+
+       /* Verify the end of the archive. */
+       assertEqualIntA(a, ARCHIVE_EOF,
+           archive_read_next_header(a, &entry));
+       assertEqualIntA(a, ARCHIVE_OK, archive_read_close(a));
+       assertEqualInt(ARCHIVE_OK, archive_read_free(a));
+
+}
+
+DEFINE_TEST(test_write_format_tar_empty_dirname)
+{
+       test_format(archive_write_set_format_gnutar);
+       test_format(archive_write_set_format_pax);
+       test_format(archive_write_set_format_ustar);
+       test_format(archive_write_set_format_v7tar);
+}