diff options
authorPablo Neira Ayuso <>2015-07-17 14:38:37 +0200
committerPablo Neira Ayuso <>2015-07-17 14:42:50 +0200
commitefd09355038d53fdd3841ab5ccae1543c4967daf (patch)
parent1ddd74855032015195a8d87c0b650f1ce73db375 (diff)
netlink_delinearize: meta l4proto range printing broken on 32bit
Florian Westphal says: 09565a4b1ed4863d44c4509a93c50f44efd12771 ("netlink_delinearize: consolidate range printing") causes nft to segfault on 32bit machine when printing l4proto ranges. The problem is that meta_expr_pctx_update() assumes that right is a value, but after this change it can also be a range. Thus, expr->value contents are undefined (its union). On x86_64 this is also broken but by virtue of struct layout and pointer sizes, value->_mp_size will almost always be 0 so mpz_get_uint8() returns 0. But on x86-32 _mp_size will be huge value (contains expr->right pointer of range), so we crash in libgmp. Pablo says: We shouldn't call pctx_update(), before the transformation we had there a expr->op == { OP_GT, OP_GTE, OP_LT, OP_LTE }. So we never entered that path as the assert in payload_expr_pctx_update() indicates. Signed-off-by: Pablo Neira Ayuso <> Tested-by: Florian Westphal <>
1 files changed, 3 insertions, 0 deletions
diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index 6d60be32..4226b822 100644
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -983,6 +983,9 @@ static void meta_match_postprocess(struct rule_pp_ctx *ctx,
switch (expr->op) {
case OP_EQ:
+ if (expr->right->ops->type == EXPR_RANGE)
+ break;
expr->left->ops->pctx_update(&ctx->pctx, expr);
if (ctx->pbase == PROTO_BASE_INVALID &&