| |
| |
| @@ -156,7 +156,8 @@ |
| .It Fl Fl insecure |
| (i and p mode only) |
| Disable security checks during extraction or copying. |
| -This allows extraction via symbolic links and path names containing |
| +This allows extraction via symbolic links, absolute paths, |
| +and path names containing |
| .Sq .. |
| in the name. |
| .It Fl J , Fl Fl xz |
| |
| |
| @@ -179,6 +179,7 @@ |
| cpio->extract_flags |= ARCHIVE_EXTRACT_NO_OVERWRITE_NEWER; |
| cpio->extract_flags |= ARCHIVE_EXTRACT_SECURE_SYMLINKS; |
| cpio->extract_flags |= ARCHIVE_EXTRACT_SECURE_NODOTDOT; |
| + cpio->extract_flags |= ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS; |
| cpio->extract_flags |= ARCHIVE_EXTRACT_PERM; |
| cpio->extract_flags |= ARCHIVE_EXTRACT_FFLAGS; |
| cpio->extract_flags |= ARCHIVE_EXTRACT_ACL; |
| @@ -264,6 +265,7 @@ |
| case OPTION_INSECURE: |
| cpio->extract_flags &= ~ARCHIVE_EXTRACT_SECURE_SYMLINKS; |
| cpio->extract_flags &= ~ARCHIVE_EXTRACT_SECURE_NODOTDOT; |
| + cpio->extract_flags &= ~ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS; |
| break; |
| case 'L': /* GNU cpio */ |
| cpio->option_follow_links = 1; |
| @@ -300,6 +302,7 @@ |
| "Cannot use both -p and -%c", cpio->mode); |
| cpio->mode = opt; |
| cpio->extract_flags &= ~ARCHIVE_EXTRACT_SECURE_NODOTDOT; |
| + cpio->extract_flags &= ~ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS; |
| break; |
| case OPTION_PRESERVE_OWNER: |
| cpio->extract_flags |= ARCHIVE_EXTRACT_OWNER; |
| |
| |
| @@ -562,6 +562,8 @@ |
| /* Default: Do not use HFS+ compression if it was not compressed. */ |
| /* This has no effect except on Mac OS v10.6 or later. */ |
| #define ARCHIVE_EXTRACT_HFS_COMPRESSION_FORCED (0x8000) |
| +/* Default: Do not reject entries with absolute paths */ |
| +#define ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS (0x10000) |
| |
| __LA_DECL int archive_read_extract(struct archive *, struct archive_entry *, |
| int flags); |
| |
| |
| @@ -177,6 +177,9 @@ |
| Note that paths ending in |
| .Pa .. |
| always cause an error, regardless of this flag. |
| +.It Cm ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS |
| +Refuse to extract an absolute path. |
| +The default is to not refuse such paths. |
| .It Cm ARCHIVE_EXTRACT_SPARSE |
| Scan data for blocks of NUL bytes and try to recreate them with holes. |
| This results in sparse files, independent of whether the archive format |
| |
| |
| @@ -2504,8 +2504,9 @@ |
| /* |
| * Canonicalize the pathname. In particular, this strips duplicate |
| * '/' characters, '.' elements, and trailing '/'. It also raises an |
| - * error for an empty path, a trailing '..' or (if _SECURE_NODOTDOT is |
| - * set) any '..' in the path. |
| + * error for an empty path, a trailing '..', (if _SECURE_NODOTDOT is |
| + * set) any '..' in the path or (if ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS |
| + * is set) if the path is absolute. |
| */ |
| static int |
| cleanup_pathname(struct archive_write_disk *a) |
| @@ -2524,8 +2525,15 @@ |
| cleanup_pathname_win(a); |
| #endif |
| /* Skip leading '/'. */ |
| - if (*src == '/') |
| + if (*src == '/') { |
| + if (a->flags & ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS) { |
| + archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, |
| + "Path is absolute"); |
| + return (ARCHIVE_FAILED); |
| + } |
| + |
| separator = *src++; |
| + } |
| |
| /* Scan the pathname one element at a time. */ |
| for (;;) { |
| |
| |
| @@ -178,6 +178,29 @@ |
| assert(S_ISDIR(st.st_mode)); |
| archive_entry_free(ae); |
| |
| + /* |
| + * Without security checks, we should be able to |
| + * extract an absolute path. |
| + */ |
| + assert((ae = archive_entry_new()) != NULL); |
| + archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp"); |
| + archive_entry_set_mode(ae, S_IFREG | 0777); |
| + assert(0 == archive_write_header(a, ae)); |
| + assert(0 == archive_write_finish_entry(a)); |
| + assertFileExists("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp"); |
| + assert(0 == unlink("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp")); |
| + |
| + /* But with security checks enabled, this should fail. */ |
| + assert(archive_entry_clear(ae) != NULL); |
| + archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp"); |
| + archive_entry_set_mode(ae, S_IFREG | 0777); |
| + archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS); |
| + failure("Extracting an absolute path should fail here."); |
| + assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae)); |
| + archive_entry_free(ae); |
| + assert(0 == archive_write_finish_entry(a)); |
| + assertFileNotExists("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp"); |
| + |
| assertEqualInt(ARCHIVE_OK, archive_write_free(a)); |
| |
| /* Test the entries on disk. */ |
| |
| |
| @@ -671,8 +671,12 @@ |
| _archive_write_data(struct archive *_a, const void *buff, size_t s) |
| { |
| struct archive_write *a = (struct archive_write *)_a; |
| + const size_t max_write = INT_MAX; |
| archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC, |
| ARCHIVE_STATE_DATA, "archive_write_data"); |
| + /* In particular, this catches attempts to pass negative values. */ |
| + if (s > max_write) |
| + s = max_write; |
| archive_clear_error(&a->archive); |
| return ((a->format_write_data)(a, buff, s)); |
| } |