Merge pull request #2993 from kientzle/kientzle-zip-long-pathnames

[Zip] Don't try to write overlong pathnames

(cherry picked from commit 6fcf9b4589)

Makefile.am

@@ -684,6 +684,7 @@ libarchive_test_SOURCES= \
 	libarchive/test/test_write_format_zip_file.c \
 	libarchive/test/test_write_format_zip_file_zip64.c \
 	libarchive/test/test_write_format_zip_large.c \
+	libarchive/test/test_write_format_zip_long_pathname.c \
 	libarchive/test/test_write_format_zip_stream.c \
 	libarchive/test/test_write_format_zip_windows_path.c \
 	libarchive/test/test_write_format_zip_zip64.c \

libarchive/archive_write_set_format_zip.c

@@ -959,6 +959,11 @@ archive_write_zip_header(struct archive_write *a, struct archive_entry *entry)
 		}
 	}
 	filename_length = path_length(zip->entry);
+	if (filename_length > 0xffff) {
+		archive_set_error(&a->archive, ENAMETOOLONG,
+		    "Pathname too long for ZIP format");
+		return (ARCHIVE_FAILED);
+	}
 
 	/* Determine appropriate compression and size for this entry. */
 	if (type == AE_IFLNK) {

libarchive/test/CMakeLists.txt

@@ -318,6 +318,7 @@ IF(ENABLE_TEST)
     test_write_format_zip_file.c
     test_write_format_zip_file_zip64.c
     test_write_format_zip_large.c
+    test_write_format_zip_long_pathname.c
     test_write_format_zip_stream.c
     test_write_format_zip_windows_path.c
     test_write_format_zip_zip64.c

libarchive/test/test_write_format_zip_long_pathname.c

@@ -0,0 +1,114 @@
+/*-
+ * Copyright (c) 2026 Tim Kientzle
+ * 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"
+
+/*
+ * ZIP stores the filename length in a 16-bit field, so the maximum is
+ * 65535 bytes.  A pathname of 65536 bytes or more must be rejected
+ * (ARCHIVE_FAILED) rather than silently truncated in the header and
+ * written past the end of the central-directory segment buffer.
+ */
+DEFINE_TEST(test_write_format_zip_long_pathname)
+{
+	struct archive *a;
+	struct archive_entry *ae;
+	char *pathname;
+	char *buf;
+	size_t used;
+	/* Enough room for a valid ZIP with a 65535-byte filename. */
+	const size_t bufsize = 256 * 1024;
+
+	buf = malloc(bufsize);
+	assert(buf != NULL);
+
+	/* 65535-byte pathname: exactly the ZIP maximum — must succeed. */
+	pathname = malloc(65536);
+	assert(pathname != NULL);
+	memset(pathname, 'a', 65535);
+	pathname[65535] = '\0';
+
+	assert((a = archive_write_new()) != NULL);
+	assertEqualInt(ARCHIVE_OK, archive_write_set_format_zip(a));
+	assertEqualInt(ARCHIVE_OK,
+	    archive_write_open_memory(a, buf, bufsize, &used));
+
+	assert((ae = archive_entry_new()) != NULL);
+	archive_entry_copy_pathname(ae, pathname);
+	archive_entry_set_mode(ae, AE_IFREG | 0644);
+	archive_entry_set_size(ae, 0);
+	assertEqualInt(ARCHIVE_OK, archive_write_header(a, ae));
+	archive_entry_free(ae);
+
+	assertEqualInt(ARCHIVE_OK, archive_write_close(a));
+	assertEqualInt(ARCHIVE_OK, archive_write_free(a));
+	free(pathname);
+
+	/* 65536-byte pathname: one byte over the ZIP limit — must be rejected. */
+	pathname = malloc(65537);
+	assert(pathname != NULL);
+	memset(pathname, 'a', 65536);
+	pathname[65536] = '\0';
+
+	assert((a = archive_write_new()) != NULL);
+	assertEqualInt(ARCHIVE_OK, archive_write_set_format_zip(a));
+	assertEqualInt(ARCHIVE_OK,
+	    archive_write_open_memory(a, buf, bufsize, &used));
+
+	assert((ae = archive_entry_new()) != NULL);
+	archive_entry_copy_pathname(ae, pathname);
+	archive_entry_set_mode(ae, AE_IFREG | 0644);
+	archive_entry_set_size(ae, 0);
+	assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));
+	archive_entry_free(ae);
+
+	assertEqualInt(ARCHIVE_OK, archive_write_close(a));
+	assertEqualInt(ARCHIVE_OK, archive_write_free(a));
+	free(pathname);
+
+	/* 131072-byte pathname: the OOB-write size from the bug report. */
+	pathname = malloc(131073);
+	assert(pathname != NULL);
+	memset(pathname, 'a', 131072);
+	pathname[131072] = '\0';
+
+	assert((a = archive_write_new()) != NULL);
+	assertEqualInt(ARCHIVE_OK, archive_write_set_format_zip(a));
+	assertEqualInt(ARCHIVE_OK,
+	    archive_write_open_memory(a, buf, bufsize, &used));
+
+	assert((ae = archive_entry_new()) != NULL);
+	archive_entry_copy_pathname(ae, pathname);
+	archive_entry_set_mode(ae, AE_IFREG | 0644);
+	archive_entry_set_size(ae, 0);
+	assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));
+	archive_entry_free(ae);
+
+	assertEqualInt(ARCHIVE_OK, archive_write_close(a));
+	assertEqualInt(ARCHIVE_OK, archive_write_free(a));
+	free(pathname);
+
+	free(buf);
+}