path: root/variable.c
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authortenderlove <tenderlove@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2016-11-29 17:06:35 (GMT)
committertenderlove <tenderlove@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2016-11-29 17:06:35 (GMT)
commite04167bc32a1a085f11c12ff44a124d287b22b70 (patch)
tree1de48d14e0ea3bcdda4eb1f8ca410a5138ff8a29 /variable.c
parent716610ae565caed8df725dd26ffbc2000b673fcd (diff)
Stop reading past the end of `ivptr` array
If you have code like this: ```ruby class A def initialize @a = nil @b = nil @c = nil @d = nil @e = nil end end x = y = x.clone 100.times { |z| x.instance_variable_set(:"@foo#{z}", nil) } puts y.inspect ``` `x` and `y` will share `iv_index_tbl` hashes. However, the size of the hash will grow larger than the number if entries in `ivptr` in `y`. Before this commit, `rb_ivar_count` would use the size of the hash to determine how far to read in to the array, but this means that it could read past the end of the array and cause the program to segv [ruby-core:78403] git-svn-id: svn+ssh:// b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'variable.c')
1 files changed, 1 insertions, 1 deletions
diff --git a/variable.c b/variable.c
index e924505..91482e9 100644
--- a/variable.c
+++ b/variable.c
@@ -1619,7 +1619,7 @@ rb_ivar_count(VALUE obj)
switch (BUILTIN_TYPE(obj)) {
case T_OBJECT:
if ((tbl = ROBJECT_IV_INDEX_TBL(obj)) != 0) {
- st_index_t i, count, num = tbl->num_entries;
+ st_index_t i, count, num = ROBJECT_NUMIV(obj);
const VALUE *const ivptr = ROBJECT_IVPTR(obj);
for (i = count = 0; i < num; ++i) {
if (ivptr[i] != Qundef) {