libdw: Add overflow checking to __libdw_form_val_len.
Pass endp as argument to __libdw_form_val_len and check we don't read
beyond the end of expected data and don't return lengths that would
overflow.
Signed-off-by: Mark Wielaard <[email protected]>
diff --git a/libdw/dwarf_getmacros.c b/libdw/dwarf_getmacros.c
index bd64d60..737dc5d 100644
--- a/libdw/dwarf_getmacros.c
+++ b/libdw/dwarf_getmacros.c
@@ -367,8 +367,12 @@
attributes[i].valp = (void *) readp;
attributes[i].cu = &fake_cu;
- readp += __libdw_form_val_len (dbg, &fake_cu,
- proto->forms[i], readp);
+ size_t len = __libdw_form_val_len (dbg, &fake_cu,
+ proto->forms[i], readp, endp);
+ if (len == (size_t) -1)
+ return -1;
+
+ readp += len;
}
Dwarf_Macro macro = {
