nftables/0021-monitor-Sanitize-startup-race-condition.patch
Phil Sutter 552075b562 nftables-1.0.4-8.el9
* Thu Feb 09 2023 Phil Sutter <psutter@redhat.com> [1.0.4-8.el9]
- monitor: Sanitize startup race condition (Phil Sutter) [2130721]
- evaluate: set eval ctx for add/update statements with integer constants (Phil Sutter) [2094894]
- src: allow anon set concatenation with ether and vlan (Phil Sutter) [2094887]
- evaluate: search stacked header list for matching payload dep (Phil Sutter) [2094887]
- netlink_delinearize: also postprocess OP_AND in set element context (Phil Sutter) [2094887]
- tests: add a test case for ether and vlan listing (Phil Sutter) [2094887]
- debug: dump the l2 protocol stack (Phil Sutter) [2094887]
- proto: track full stack of seen l2 protocols, not just cumulative offset (Phil Sutter) [2094887]
- netlink_delinearize: postprocess binary ands in concatenations (Phil Sutter) [2094887]
- netlink_delinearize: allow postprocessing on concatenated elements (Phil Sutter) [2094887]
- intervals: check for EXPR_F_REMOVE in case of element mismatch (Phil Sutter) [2115627]
- intervals: fix crash when trying to remove element in empty set (Phil Sutter) [2115627]
- scanner: don't pop active flex scanner scope (Phil Sutter) [2113874]
- parser: add missing synproxy scope closure (Phil Sutter) [2113874]
- tests/py: Add a test for failing ipsec after counter (Phil Sutter) [2113874]
- doc: Document limitations of ipsec expression with xfrm_interface (Phil Sutter) [1806431]
Resolves: rhbz#1806431, rhbz#2094887, rhbz#2094894, rhbz#2113874, rhbz#2115627, rhbz#2130721, rhbz#2094890
2023-02-09 15:47:30 +01:00

108 lines
3.2 KiB
Diff

From ef0f28bc8efdc5292ceb593c9c5a646f030e0994 Mon Sep 17 00:00:00 2001
From: Phil Sutter <psutter@redhat.com>
Date: Thu, 9 Feb 2023 15:25:37 +0100
Subject: [PATCH] monitor: Sanitize startup race condition
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2130721
Upstream Status: nftables commit 545edb7a8ef0a
commit 545edb7a8ef0a8acf991b1b7857fddc24d7b151a
Author: Phil Sutter <phil@nwl.cc>
Date: Wed Sep 28 23:26:42 2022 +0200
monitor: Sanitize startup race condition
During startup, 'nft monitor' first fetches the current ruleset and then
keeps this cache up to date based on received events. This is racey, as
any ruleset changes in between the initial fetch and the socket opening
are not recognized.
This script demonstrates the problem:
| #!/bin/bash
|
| while true; do
| nft flush ruleset
| iptables-nft -A FORWARD
| done &
| maniploop=$!
|
| trap "kill $maniploop; kill \$!; wait" EXIT
|
| while true; do
| nft monitor rules >/dev/null &
| sleep 0.2
| kill $!
| done
If the table add event is missed, the rule add event callback fails to
deserialize the rule and calls abort().
Avoid the inconvenient program exit by returning NULL from
netlink_delinearize_rule() instead of aborting and make callers check
the return value.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Phil Sutter <psutter@redhat.com>
---
src/cache.c | 1 +
src/monitor.c | 5 +++++
src/netlink_delinearize.c | 5 ++++-
3 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/src/cache.c b/src/cache.c
index fd8df88..701aec6 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -490,6 +490,7 @@ static int list_rule_cb(struct nftnl_rule *nlr, void *data)
netlink_dump_rule(nlr, ctx);
rule = netlink_delinearize_rule(ctx, nlr);
+ assert(rule);
list_add_tail(&rule->list, &ctx->list);
return 0;
diff --git a/src/monitor.c b/src/monitor.c
index 7fa92eb..a6b30a1 100644
--- a/src/monitor.c
+++ b/src/monitor.c
@@ -551,6 +551,10 @@ static int netlink_events_rule_cb(const struct nlmsghdr *nlh, int type,
nlr = netlink_rule_alloc(nlh);
r = netlink_delinearize_rule(monh->ctx, nlr);
+ if (!r) {
+ fprintf(stderr, "W: Received event for an unknown table.\n");
+ goto out_free_nlr;
+ }
nlr_for_each_set(nlr, rule_map_decompose_cb, NULL,
&monh->ctx->nft->cache);
cmd = netlink_msg2cmd(type, nlh->nlmsg_flags);
@@ -587,6 +591,7 @@ static int netlink_events_rule_cb(const struct nlmsghdr *nlh, int type,
break;
}
rule_free(r);
+out_free_nlr:
nftnl_rule_free(nlr);
return MNL_CB_OK;
}
diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index c6ad84d..1d47c74 100644
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -3194,7 +3194,10 @@ struct rule *netlink_delinearize_rule(struct netlink_ctx *ctx,
pctx->rule = rule_alloc(&netlink_location, &h);
pctx->table = table_cache_find(&ctx->nft->cache.table_cache,
h.table.name, h.family);
- assert(pctx->table != NULL);
+ if (!pctx->table) {
+ errno = ENOENT;
+ return NULL;
+ }
pctx->rule->comment = nftnl_rule_get_comment(nlr);
--
2.39.1