2 files changed, 35 insertions, 20 deletions

diff --git a/archival/libunarchive/get_header_tar.c b/archival/libunarchive/get_header_tar.c
index b785d631d..583f6f811 100644
--- a/archival/libunarchive/get_header_tar.c
+++ b/archival/libunarchive/get_header_tar.c
@@ -40,11 +40,12 @@ static unsigned long long getOctal(char *str, int len)
                 bb_error_msg_and_die("corrupted octal value in tar header");
         return v;
 }
+#define GET_OCTAL(a) getOctal((a), sizeof(a))
 
 void BUG_tar_header_size(void);
 char get_header_tar(archive_handle_t *archive_handle)
 {
-        static int end = 0;
+        static int end;
 
         file_header_t *file_header = archive_handle->file_header;
         struct {
@@ -69,18 +70,17 @@ char get_header_tar(archive_handle_t *archive_handle)
         } tar;
         char *cp;
         int sum, i;
-#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
         int parse_names;
-#else
-        enum { parse_names = 1 };
-#endif
 
         if (sizeof(tar) != 512)
                 BUG_tar_header_size();
+ again:
 
         /* Align header */
         data_align(archive_handle, 512);
 
+ again_after_align:
+
         xread(archive_handle->src_fd, &tar, 512);
         archive_handle->offset += 512;
 
@@ -121,13 +121,12 @@ char get_header_tar(archive_handle_t *archive_handle)
                 bb_error_msg_and_die("invalid tar header checksum");
         }
 
-#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
-        parse_names = (tar.typeflag != 'L' && tar.typeflag != 'K');
-#endif
+        /* 0 is reserved for high perf file, treat as normal file */
+        if (!tar.typeflag) tar.typeflag = '0';
+        parse_names = (tar.typeflag >= '0' && tar.typeflag <= '7');
 
         /* getOctal trashes subsequent field, therefore we call it
          * on fields in reverse order */
-#define GET_OCTAL(a) getOctal((a), sizeof(a))
         if (tar.devmajor[0]) {
                 unsigned minor = GET_OCTAL(tar.devminor);
                 unsigned major = GET_OCTAL(tar.devmajor);
@@ -147,8 +146,8 @@ char get_header_tar(archive_handle_t *archive_handle)
         file_header->uid = GET_OCTAL(tar.uid);
         /* Set bits 0-11 of the files mode */
         file_header->mode = 07777 & GET_OCTAL(tar.mode);
-#undef GET_OCTAL
 
+        file_header->name = NULL;
         if (!longname && parse_names) {
                 /* we trash mode[0] here, it's ok */
                 tar.name[sizeof(tar.name)] = '\0';
@@ -158,6 +157,7 @@ char get_header_tar(archive_handle_t *archive_handle)
                         file_header->name = concat_path_file(tar.prefix, tar.name);
                 } else
                         file_header->name = xstrdup(tar.name);
+                /* FIXME: add check for /../ attacks */
         }
 
         /* Set bits 12-15 of the files mode */
@@ -168,8 +168,7 @@ char get_header_tar(archive_handle_t *archive_handle)
                 file_header->mode |= S_IFREG;
                 break;
         case '7':
-                /* Reserved for high performance files, treat as normal file */
-        case 0:
+        /* case 0: */
         case '0':
 #if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
                 if (last_char_is(file_header->name, '/')) {
@@ -195,18 +194,24 @@ char get_header_tar(archive_handle_t *archive_handle)
                 break;
 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
         case 'L':
-                /* paranoia: tar with several consecutive longnames */
+                /* free: paranoia: tar with several consecutive longnames */
                 free(longname);
+                /* For paranoia reasons we allocate extra NUL char */
                 longname = xzalloc(file_header->size + 1);
+                /* We read ASCIZ string, including NUL */
                 xread(archive_handle->src_fd, longname, file_header->size);
                 archive_handle->offset += file_header->size;
-                return get_header_tar(archive_handle);
+                /* return get_header_tar(archive_handle); */
+                /* gcc 4.1.1 didn't optimize it into jump */
+                /* so we will do it ourself, this also saves stack */
+                goto again;
         case 'K':
                 free(linkname);
                 linkname = xzalloc(file_header->size + 1);
                 xread(archive_handle->src_fd, linkname, file_header->size);
                 archive_handle->offset += file_header->size;
-                return get_header_tar(archive_handle);
+                /* return get_header_tar(archive_handle); */
+                goto again;
         case 'D':       /* GNU dump dir */
         case 'M':       /* Continuation of multi volume archive */
         case 'N':       /* Old GNU for names > 100 characters */
@@ -214,11 +219,19 @@ char get_header_tar(archive_handle_t *archive_handle)
         case 'V':       /* Volume header */
 #endif
         case 'g':       /* pax global header */
-        case 'x':       /* pax extended header */
-                bb_error_msg("ignoring extension type %c", tar.typeflag);
-                break;
+        case 'x': {     /* pax extended header */
+                off_t sz;
+                bb_error_msg("warning: skipping header '%c'", tar.typeflag);
+                sz = (file_header->size + 511) & ~(off_t)511;
+                archive_handle->offset += sz;
+                sz >>= 9; /* sz /= 512 but w/o contortions for signed div */
+                while (sz--)
+                        xread(archive_handle->src_fd, &tar, 512);
+                /* return get_header_tar(archive_handle); */
+                goto again_after_align;
+        }
         default:
-                bb_error_msg("unknown typeflag: 0x%x", tar.typeflag);
+                bb_error_msg_and_die("unknown typeflag: 0x%x", tar.typeflag);
         }
 
 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
@@ -246,10 +259,12 @@ char get_header_tar(archive_handle_t *archive_handle)
                 llist_add_to(&(archive_handle->passed), file_header->name);
         } else {
                 data_skip(archive_handle);
+                free(file_header->name);
         }
         archive_handle->offset += file_header->size;
 
         free(file_header->link_name);
+        /* Do not free(file_header->name)! */
 
         return EXIT_SUCCESS;
 }
diff --git a/archival/tar.c b/archival/tar.c
index bf6786f0a..48a1c34cd 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -768,7 +768,7 @@ int tar_main(int argc, char **argv)
         if (verboseFlag) tar_handle->action_header = header_verbose_list;
         if (verboseFlag == 1) tar_handle->action_header = header_list;
 
-        if ((opt & OPT_EXTRACT) && tar_handle->action_data != data_extract_to_stdout)
+        if (opt & OPT_EXTRACT)
                 tar_handle->action_data = data_extract_all;
 
         if (opt & OPT_2STDOUT)