merge revision(s) 66832: [Backport #15536]

	st.c (rb_hash_bulk_insert_into_st_table): avoid out-of-bounds write

	"hash_bulk_insert" first expands the table, but the target size was
	wrong: it was calculated by "num_entries + (size to buld insert)", but
	it was wrong when "num_entries < entries_bound", i.e., it has a deleted
	entry.  "hash_bulk_insert" adds the given entries from entries_bound,
	which led to out-of-bounds write access.  [Bug #15536]

	As a simple fix, this commit changes the calculation to "entries_bound +
	size".  I'm afraid if this might be inefficient, but I think it is safe
	anyway.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_5@67236 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 1 deletions

diff --git a/st.c b/st.c
index 9740e02d59..d44c979e19 100644
--- a/st.c
+++ b/st.c
@@ -2292,7 +2292,7 @@ rb_hash_bulk_insert(long argc, const VALUE *argv, VALUE hash)
         RHASH(hash)->ntbl = tab = RHASH(tmp)->ntbl;
         RHASH(tmp)->ntbl = NULL;
     }
-    n = tab->num_entries + argc / 2;
+    n = tab->entries_bound + argc / 2;
     st_expand_table(tab, n);
     if (UNLIKELY(tab->num_entries))
         st_insert_generic(tab, argc, argv, hash);