We release ->dtype twice, will either segfault or assert
on dtype->refcount != 0 check in datatype_free().
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
src/evaluate.c | 2 +-
.../bogons/nft-f/double-free-on-binop-dtype_assert | 6 ++++++
2 files changed, 7 insertions(+), 1 deletion(-)
create mode 100644 tests/shell/testcases/bogons/nft-f/double-free-on-binop-dtype_assert
diff --git a/src/evaluate.c b/src/evaluate.c
index 16ad6473db1a..58cc811aca9a 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -1171,7 +1171,7 @@ static int expr_evaluate_prefix(struct eval_ctx *ctx, struct expr **expr)
base = prefix->prefix;
assert(expr_is_constant(base));
- prefix->dtype = base->dtype;
+ prefix->dtype = datatype_get(base->dtype);
prefix->byteorder = base->byteorder;
prefix->len = base->len;
prefix->flags |= EXPR_F_CONSTANT;
diff --git a/tests/shell/testcases/bogons/nft-f/double-free-on-binop-dtype_assert b/tests/shell/testcases/bogons/nft-f/double-free-on-binop-dtype_assert
new file mode 100644
index 000000000000..b7a9a1cc7e8b
--- /dev/null
+++ b/tests/shell/testcases/bogons/nft-f/double-free-on-binop-dtype_assert
@@ -0,0 +1,6 @@
+table inet t {
+ chain c {
+ udp length . @th,160,118 vmap { 47-63 . 0xe3731353631303331313037353532/3 : accept }
+ jump noexist # only here so this fails to load after patch.
+ }
+}
--
2.41.0
