tar reader: treat empty archives with a GNU volume header as valid

Fixes #1062

diff --git a/Makefile.am b/Makefile.am
index 8bd821cbd29c7039920c91d4de2279512071ba91..932a5a894bfd2369a829e85467b6f1f6abe2dc0b 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -502,6 +502,7 @@ libarchive_test_SOURCES= \
        libarchive/test/test_read_format_tar_concatenated.c \
        libarchive/test/test_read_format_tar_empty_pax.c \
        libarchive/test/test_read_format_tar_empty_filename.c \
+       libarchive/test/test_read_format_tar_empty_with_gnulabel.c \
        libarchive/test/test_read_format_tar_filename.c \
        libarchive/test/test_read_format_tbz.c \
        libarchive/test/test_read_format_tgz.c \
@@ -867,6 +868,7 @@ libarchive_test_EXTRA_DIST=\
        libarchive/test/test_read_format_raw.data.uu \
        libarchive/test/test_read_format_tar_concatenated.tar.uu \
        libarchive/test/test_read_format_tar_empty_filename.tar.uu \
+       libarchive/test/test_read_format_tar_empty_with_gnulabel.tar.uu \
        libarchive/test/test_read_format_tar_empty_pax.tar.Z.uu \
        libarchive/test/test_read_format_tar_filename_koi8r.tar.Z.uu \
        libarchive/test/test_read_format_ustar_filename_cp866.tar.Z.uu \

diff --git a/libarchive/archive_read_support_format_tar.c b/libarchive/archive_read_support_format_tar.c
index 81c03c885939dfb0cd344ff4dae3a647e2909185..c63d46fc0ce2b2a64e7c0ed5c875872ea872db57 100644 (file)
--- a/libarchive/archive_read_support_format_tar.c
+++ b/libarchive/archive_read_support_format_tar.c
@@ -694,11 +694,13 @@ tar_read_header(struct archive_read *a, struct tar *tar,
     struct archive_entry *entry, size_t *unconsumed)
 {
        ssize_t bytes;
-       int err;
+       int err, eof_vol_header;
        const char *h;
        const struct archive_entry_header_ustar *header;
        const struct archive_entry_header_gnutar *gnuheader;
 
+       eof_vol_header = 0;
+
        /* Loop until we find a workable header record. */
        for (;;) {
                tar_flush_unconsumed(a, unconsumed);
@@ -788,6 +790,8 @@ tar_read_header(struct archive_read *a, struct tar *tar,
                break;
        case 'V': /* GNU volume header */
                err = header_volume(a, tar, entry, h, unconsumed);
+               if (err == ARCHIVE_EOF)
+                       eof_vol_header = 1;
                break;
        case 'X': /* Used by SUN tar; same as 'x'. */
                a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
@@ -862,9 +866,17 @@ tar_read_header(struct archive_read *a, struct tar *tar,
                }
                return (err);
        }
-       if (err == ARCHIVE_EOF)
-               /* EOF when recursively reading a header is bad. */
-               archive_set_error(&a->archive, EINVAL, "Damaged tar archive");
+       if (err == ARCHIVE_EOF) {
+               if (!eof_vol_header) {
+                       /* EOF when recursively reading a header is bad. */
+                       archive_set_error(&a->archive, EINVAL,
+                           "Damaged tar archive");
+               } else {
+                       /* If we encounter just a GNU volume header treat
+                        * this situation as an empty archive */
+                       return (ARCHIVE_EOF);
+               }
+       }
        return (ARCHIVE_FATAL);
 }
 

diff --git a/libarchive/test/CMakeLists.txt b/libarchive/test/CMakeLists.txt
index c6c95aa563fbb7acb88edf89bfca186cddf4bd52..80452b654a7c5cc26e61bbf5516b664c8970f833 100644 (file)
--- a/libarchive/test/CMakeLists.txt
+++ b/libarchive/test/CMakeLists.txt
@@ -154,6 +154,7 @@ IF(ENABLE_TEST)
     test_read_format_tar.c
     test_read_format_tar_concatenated.c
     test_read_format_tar_empty_filename.c
+    test_read_format_tar_empty_with_gnulabel.c
     test_read_format_tar_empty_pax.c
     test_read_format_tar_filename.c
     test_read_format_tbz.c

diff --git a/libarchive/test/test_read_format_tar_empty_with_gnulabel.c b/libarchive/test/test_read_format_tar_empty_with_gnulabel.c
new file mode 100644 (file)
index 0000000..83f20bb
--- /dev/null
+++ b/libarchive/test/test_read_format_tar_empty_with_gnulabel.c
@@ -0,0 +1,53 @@
+/*-
+ * Copyright (c) 2019 Martin Matuska
+ * 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"
+__FBSDID("$FreeBSD$");
+
+/*
+ * Tar archives with with just a GNU label (or ending with one) should
+ * be treated as valid (empty) archives
+ */
+DEFINE_TEST(test_read_format_tar_empty_with_gnulabel)
+{
+       char name[] = "test_read_format_tar_empty_with_gnulabel.tar";
+       struct archive_entry *ae;
+       struct archive *a;
+
+       assert((a = archive_read_new()) != NULL);
+       assertEqualIntA(a, ARCHIVE_OK, archive_read_support_filter_all(a));
+       assertEqualIntA(a, ARCHIVE_OK, archive_read_support_format_all(a));
+       extract_reference_file(name);
+       assertEqualIntA(a, ARCHIVE_OK, archive_read_open_filename(a, name, 10240));
+
+       /* Read first entry. */
+       assertEqualIntA(a, ARCHIVE_EOF, archive_read_next_header(a, &ae));
+
+       /* Verify that the format detection worked. */
+       assertEqualInt(archive_filter_code(a, 0), ARCHIVE_FILTER_NONE);
+       assertEqualInt(archive_format(a), ARCHIVE_FORMAT_TAR);
+
+       assertEqualInt(ARCHIVE_OK, archive_read_close(a));
+       assertEqualInt(ARCHIVE_OK, archive_read_free(a));
+}

diff --git a/libarchive/test/test_read_format_tar_empty_with_gnulabel.tar.uu b/libarchive/test/test_read_format_tar_empty_with_gnulabel.tar.uu
new file mode 100644 (file)
index 0000000..c5aa393
--- /dev/null
+++ b/libarchive/test/test_read_format_tar_empty_with_gnulabel.tar.uu
@@ -0,0 +1,231 @@
+begin 664 test_read_format_tar_empty_with_gnulabel.tar
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+end