libdw: Check DIE address fall inside the CU before reading abbrev code.

The afl fuzzer found a case where we tried reading an uleb for the DIE
abbrev code without properly checking the DIE address is inside the CU.

Signed-off-by: Mark Wielaard <mark@klomp.org>

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index b000492..b569393 100644 (file)
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,5 +1,9 @@
 2018-06-06  Mark Wielaard  <mark@klomp.org>
 
+       * libdwP.h (__libdw_dieabbrev): Check DIE addr falls in cu.
+
+2018-06-06  Mark Wielaard  <mark@klomp.org>
+
        * dwarf_getlocation_die.c (dwarf_getlocation_die): Check offset
        falls inside cu data.
 

diff --git a/libdw/libdwP.h b/libdw/libdwP.h
index 1c8dd0d..3d8e145 100644 (file)
--- a/libdw/libdwP.h
+++ b/libdw/libdwP.h
@@ -653,7 +653,7 @@ __libdw_dieabbrev (Dwarf_Die *die, const unsigned char **readp)
       /* Get the abbreviation code.  */
       unsigned int code;
       const unsigned char *addr = die->addr;
-      if (die->cu == NULL)
+      if (die->cu == NULL || addr >= (const unsigned char *) die->cu->endp)
        return DWARF_END_ABBREV;
       get_uleb128 (code, addr, die->cu->endp);
       if (readp != NULL)