Changeset 3621 in MondoRescue for branches/3.3/mindi-busybox/archival/libarchive/get_header_ar.c

Timestamp:

Dec 20, 2016, 4:07:32 PM (7 years ago)

Author:

Bruno Cornec

Message:

New 3?3 banch for incorporation of latest busybox 1.25. Changing minor version to handle potential incompatibilities.

Location:

branches/3.3

Files:

• . (copied) (copied from branches/3.2 )
• mindi-busybox/archival/libarchive/get_header_ar.c (modified) (4 diffs)

branches/3.3/mindi-busybox/archival/libarchive/get_header_ar.c

@@ -9 +9 @@
 #include "ar.h"
 
-static unsigned read_num(const char *str, int base)
+/* WARNING: Clobbers str[len], so fields must be read in reverse order! */
+static unsigned read_num(char *str, int base, int len)
 {
+    int err;
+
+    /* ar fields are fixed length text strings (padded with spaces).
+     * Ensure bb_strtou doesn't read past the field in case the full
+     * width is used. */
+    str[len] = 0;
+
     /* This code works because
      * on misformatted numbers bb_strtou returns all-ones */
-    int err = bb_strtou(str, NULL, base);
+    err = bb_strtou(str, NULL, base);
     if (err == -1)
         bb_error_msg_and_die("invalid ar header");
@@ -52 +60 @@
         bb_error_msg_and_die("invalid ar header");
 
-    /* FIXME: more thorough routine would be in order here
-     * (we have something like that in tar)
-     * but for now we are lax. */
-    ar.formatted.magic[0] = '\0'; /* else 4G-2 file will have size="4294967294`\n..." */
-    typed->size = size = read_num(ar.formatted.size, 10);
+    /*
+     * Note that the fields MUST be read in reverse order as
+     * read_num() clobbers the next byte after the field!
+     * Order is: name, date, uid, gid, mode, size, magic.
+     */
+    typed->size = size = read_num(ar.formatted.size, 10,
+                      sizeof(ar.formatted.size));
 
     /* special filenames have '/' as the first character */
@@ -88 +98 @@
      * after dealing with long filename pseudo file.
      */
-    typed->mode = read_num(ar.formatted.mode, 8);
-    typed->mtime = read_num(ar.formatted.date, 10);
-    typed->uid = read_num(ar.formatted.uid, 10);
-    typed->gid = read_num(ar.formatted.gid, 10);
+    typed->mode = read_num(ar.formatted.mode, 8, sizeof(ar.formatted.mode));
+    typed->gid = read_num(ar.formatted.gid, 10, sizeof(ar.formatted.gid));
+    typed->uid = read_num(ar.formatted.uid, 10, sizeof(ar.formatted.uid));
+    typed->mtime = read_num(ar.formatted.date, 10, sizeof(ar.formatted.date));
 
 #if ENABLE_FEATURE_AR_LONG_FILENAMES
@@ -99 +109 @@
         /* The number after the '/' indicates the offset in the ar data section
          * (saved in ar_long_names) that conatains the real filename */
-        long_offset = read_num(&ar.formatted.name[1], 10);
+        long_offset = read_num(&ar.formatted.name[1], 10,
+                       sizeof(ar.formatted.name) - 1);
         if (long_offset >= ar_long_name_size) {
             bb_error_msg_and_die("can't resolve long filename");