resolv: ns_name_pton should report trailing \ as error [BZ #22413]

diff --git a/ChangeLog b/ChangeLog
index 5ddb6fd..4739e62 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2017-11-11  Florian Weimer  <fweimer@redhat.com>
 
+       [BZ #22413]
+       * resolv/ns_name.c (ns_name_pton): Treat trailing backslash as error.
+       * resolv/tst-ns_name_pton.c (tests): Add trailing backslash tests.
+
+2017-11-11  Florian Weimer  <fweimer@redhat.com>
+
        * resolv/tst-ns_name_pton.c: New file.
        * resolv/Makefile (tests): Add tst-ns_name_pton.
        (tst-ns_name_pton): Link against libresolv.

diff --git a/resolv/ns_name.c b/resolv/ns_name.c
index 08a75e2..73213fe 100644 (file)
--- a/resolv/ns_name.c
+++ b/resolv/ns_name.c
@@ -222,6 +222,11 @@ ns_name_pton(const char *src, u_char *dst, size_t dstsiz)
                }
                *bp++ = (u_char)c;
        }
+       if (escaped) {
+               /* Trailing backslash.  */
+               __set_errno (EMSGSIZE);
+               return -1;
+       }
        c = (bp - label - 1);
        if ((c & NS_CMPRSFLGS) != 0) {          /*%< Label too big. */
                __set_errno (EMSGSIZE);

diff --git a/resolv/tst-ns_name_pton.c b/resolv/tst-ns_name_pton.c
index 879d97c..73bdb05 100644 (file)
--- a/resolv/tst-ns_name_pton.c
+++ b/resolv/tst-ns_name_pton.c
@@ -127,6 +127,13 @@ static const struct test_case tests[] =
       "\377\377", NULL, },
     { STRING63OCT "." STRING63OCT "." STRING63OCT "." STRING60OCT
       "\377\377\377", NULL, },
+    { "\\", NULL, },
+    { "\\\\", "\\\\", false },
+    { "\\\\.", "\\\\", true },
+    { "\\\\\\", NULL, },
+    { "a\\", NULL, },
+    { "a.\\", NULL, },
+    { "a.b\\", NULL, },
   };
 
 static int