libdw: Make sure all attributes come with a (fake) CU for bound checks.
All attributes now have a reference to a (fake) CU that has startp and
endp set to the data section where the form data comes from. Use that
for bounds checking in __libdw_form_val_len and dwarf_formblock to make
sure data read doesn't overflow any data section. Remove libdwP.h cu_data
and use cu startp and endp directly where appropriate.
Signed-off-by: Mark Wielaard <[email protected]>
diff --git a/libdw/dwarf_getmacros.c b/libdw/dwarf_getmacros.c
index 737dc5d..848128e 100644
--- a/libdw/dwarf_getmacros.c
+++ b/libdw/dwarf_getmacros.c
@@ -354,6 +354,8 @@
.dbg = dbg,
.version = 4,
.offset_size = table->is_64bit ? 8 : 4,
+ .startp = (void *) startp + offset,
+ .endp = (void *) endp,
};
Dwarf_Attribute attributes[proto->nforms];
@@ -367,8 +369,7 @@
attributes[i].valp = (void *) readp;
attributes[i].cu = &fake_cu;
- size_t len = __libdw_form_val_len (dbg, &fake_cu,
- proto->forms[i], readp, endp);
+ size_t len = __libdw_form_val_len (&fake_cu, proto->forms[i], readp);
if (len == (size_t) -1)
return -1;
