From: Steffen Klassert <steffen.klassert@secunet.com> stable inclusion from stable-v6.6.136 commit b66920a3348c0f63ba18365248fa21fbf0b3a937 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14643 CVE: CVE-2026-43091 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 069daad4f2ae9c5c108131995529d5f02392c446 ] xfrm_policy_fini() frees the policy_bydst hash tables after flushing the policy work items and deleting all policies, but it does not wait for concurrent RCU readers to leave their read-side critical sections first. The policy_bydst tables are published via rcu_assign_pointer() and are looked up through rcu_dereference_check(), so netns teardown must also wait for an RCU grace period before freeing the table memory. Fix this by adding synchronize_rcu() before freeing the policy hash tables. Fixes: e1e551bc5630 ("xfrm: policy: prepare policy_bydst hash for rcu lookups") Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> --- net/xfrm/xfrm_policy.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index bd3d698887eb..8e6383b95d6f 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -4129,6 +4129,8 @@ static void xfrm_policy_fini(struct net *net) #endif xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, false); + synchronize_rcu(); + WARN_ON(!list_empty(&net->xfrm.policy_all)); for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { -- 2.43.0