From: Florian Westphal Date: Tue, 5 Dec 2023 12:08:17 +0000 (+0100) Subject: evaluate: fix double free on dtype release X-Git-Tag: v1.0.6.1~311 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9f10130418564a832e3a8e9d25c9ec783f485358;p=thirdparty%2Fnftables.git evaluate: fix double free on dtype release commit ee73e9dcd46dc5a1fe3be7caa8b9323819e394b8 upstream. We release ->dtype twice, will either segfault or assert on dtype->refcount != 0 check in datatype_free(). Signed-off-by: Florian Westphal --- diff --git a/src/evaluate.c b/src/evaluate.c index a5c95426..fbba4be2 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -1038,7 +1038,7 @@ 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 00000000..b7a9a1cc --- /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. + } +}