dwarf_child (__libdw_find_attr), dwarf_getabbrevattr[_data] and
dwarf_getattrs all assume the end of the attribute list is when
both the name (code) and form of the attribute are zero.
dwarf_getabbrev (__libdw_getabbrev) and dwarf_hasattr assume the
end of the attribute list is when either the name (code) or the
form of the attribute is zero.
The DWARF spec says: "The series of attribute specifications ends
with an entry containing 0 for the name and 0 for the form." So
the first check is correct.
Make sure dwarf_getabbrev and dwarf_hasattr use the same check.
This is important since all other functions expect dwarf_getabbrev
(__libdw_getabbrev) to have done a data sanity check of the attribute.
So if the ending condition is different it could cause a crash.
https://sourceware.org/bugzilla/show_bug.cgi?id=23529
Signed-off-by: Mark Wielaard <mark@klomp.org>
2018-08-18 Mark Wielaard <mark@klomp.org>
+ * dwarf_getabbrev.c (__libdw_getabbrev): Continue until both name
+ and form are zero.
+ * dwarf_hasattr.c (dwarf_hasattr): Stop when both name and form
+ are zero.
+
+2018-08-18 Mark Wielaard <mark@klomp.org>
+
* dwarf_getaranges.c (dwarf_getaranges.c): Make sure there is enough
data to read the address and segment size.
get_sleb128 (formval, abbrevp, end);
}
}
- while (attrname != 0 && attrform != 0);
+ while (attrname != 0 || attrform != 0);
/* Return the length to the caller if she asked for it. */
if (lengthp != NULL)
unsigned int attr_form;
get_uleb128_unchecked (attr_form, attrp);
- /* We can stop if we found the attribute with value zero. */
- if (attr_name == 0 || attr_form == 0)
+ /* We can stop if we found the end of the attribute list. */
+ if (attr_name == 0 && attr_form == 0)
return 0;
if (attr_name == search_name)