From 23a5147a32733f75548526e9b8769cd1157b34f8 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Fri, 17 Jul 2026 11:08:41 +0200 Subject: [PATCH] evaluate: fix stack overflow with huge priority string JIRA: https://issues.redhat.com/browse/RHEL-190549 Upstream Status: nftables commit b626c86abaf294fcf1ec788f722071dc90da68c4 commit b626c86abaf294fcf1ec788f722071dc90da68c4 Author: Florian Westphal Date: Fri Dec 15 10:19:02 2023 +0100 evaluate: fix stack overflow with huge priority string Alternative would be to refactor this and move this into the parsers (bison, json) instead of this hidden re-parsing. Fixes: 627c451b2351 ("src: allow variables in the chain priority specification") Signed-off-by: Florian Westphal Signed-off-by: Phil Sutter --- src/evaluate.c | 2 +- tests/shell/testcases/bogons/nft-f/huge_chain_prio | 5 +++++ 2 files changed, 6 insertions(+), 1 deletion(-) create mode 100644 tests/shell/testcases/bogons/nft-f/huge_chain_prio diff --git a/src/evaluate.c b/src/evaluate.c index 1a8c815..c655e3a 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -4820,7 +4820,7 @@ static bool evaluate_priority(struct eval_ctx *ctx, struct prio_spec *prio, NFT_NAME_MAXLEN); loc = prio->expr->location; - if (sscanf(prio_str, "%s %c %d", prio_fst, &op, &prio_snd) < 3) { + if (sscanf(prio_str, "%255s %c %d", prio_fst, &op, &prio_snd) < 3) { priority = std_prio_lookup(prio_str, family, hook); if (priority == NF_IP_PRI_LAST) return false; diff --git a/tests/shell/testcases/bogons/nft-f/huge_chain_prio b/tests/shell/testcases/bogons/nft-f/huge_chain_prio new file mode 100644 index 0000000..41f8061 --- /dev/null +++ b/tests/shell/testcases/bogons/nft-f/huge_chain_prio @@ -0,0 +1,5 @@ +table t { + chain c { + type filter hook input priority srcnDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD#DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD; policy accept; + } +}