Bug#904749: make-dfsg: diff for NMU version 4.2.1-1.2

[ben]

Control: tags 904749 + pending

Dear maintainer,

I've prepared an NMU for make-dfsg (versioned as 4.2.1-1.2) and
uploaded it to DELAYED/2. Please feel free to tell me if I
should delay it longer.

Regards.

diff -u make-dfsg-4.2.1/arscan.c make-dfsg-4.2.1/arscan.c
--- make-dfsg-4.2.1/arscan.c
+++ make-dfsg-4.2.1/arscan.c
@@ -414,6 +414,7 @@
 # endif
 #endif
   char *namemap = 0;
+  int namemap_size = 0;
   int desc = open (archive, O_RDONLY, 0);
   if (desc < 0)
     return -1;
@@ -667,10 +668,15 @@
               && namemap != 0)
             {
               int name_off = atoi (name + 1);
-              if (name_off < 1 || name_off > ARNAME_MAX)
+              int name_len;
+
+              if (name_off < 0 || name_off >= namemap_size)
                 goto invalid;
 
               name = namemap + name_off;
+              name_len = strlen (name);
+              if (name_len < 1)
+                goto invalid;
               long_name = 1;
             }
           else if (name[0] == '#'
@@ -678,7 +684,8 @@
                    && name[2] == '/')
             {
               int name_len = atoi (name + 3);
-              if (name_len < 1 || name_len > ARNAME_MAX)
+
+              if (name_len < 1 || name_len > INT_MAX)
                 goto invalid;
 
               name = alloca (name_len + 1);
@@ -747,10 +754,13 @@
             char *clear;
             char *limit;
 
-            namemap = alloca (eltsize);
+            if (eltsize > INT_MAX)
+              goto invalid;
+            namemap = alloca (eltsize + 1);
             EINTRLOOP (nread, read (desc, namemap, eltsize));
             if (nread != eltsize)
               goto invalid;
+            namemap_size = eltsize;
 
             /* The names are separated by newlines.  Some formats have
                a trailing slash.  Null terminate the strings for
@@ -765,6 +775,7 @@
                       clear[-1] = '\0';
                   }
               }
+            *limit = '\0';
 
             is_namemap = 0;
           }
diff -u make-dfsg-4.2.1/debian/changelog make-dfsg-4.2.1/debian/changelog
--- make-dfsg-4.2.1/debian/changelog
+++ make-dfsg-4.2.1/debian/changelog
@@ -1,3 +1,11 @@
+make-dfsg (4.2.1-1.2) unstable; urgency=medium
+
+  * Non-maintainer upload.
+  * Fix validation of long names in archives (regression in 4.2.1-1.1)
+    (Closes: #904749)
+
+ -- Ben Hutchings <b...@decadent.org.uk>  Sat, 28 Jul 2018 18:07:31 +0800
+
 make-dfsg (4.2.1-1.1) unstable; urgency=medium
 
   * Non-maintainer upload