From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8F8D8359A91 for ; Sat, 28 Feb 2026 18:14:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302480; cv=none; b=DkdqAC2oCnd42w34Lm1bcSI7r/G3QxlJr0mduHJmKDjKZaH6/FRzzSOjesskgMD9tRhRJyV9lhwMoo7YIGXziJMUkhwapkMkdzO30UYsEUz9opezyMzYt0RnRxa311DcldjHQRrUWca4mzkb80EYBt0TFi5XD5lESQsJQp7wCzA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302480; c=relaxed/simple; bh=nyHbfN+xScB/1FT0MnfMknEdHC7MxVEItiM2iT70C20=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sthQcfsA/qO0Ae0lixfhszYk3R9lHrvn6Yda5ipd1LpeQzufR5z8W48YGKtnkSGL/ZwSFy6OPQj2HQn9xY7JEHiUx0w89e78RHxmVHMZ0DBzVmlabKRVZM05+zKeEz9qQlM122Aib48j+iZig+9dlnvqRt8xOCHkKHIOlLYuYfg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VgToqUG2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VgToqUG2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C13FCC19423; Sat, 28 Feb 2026 18:14:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772302480; bh=nyHbfN+xScB/1FT0MnfMknEdHC7MxVEItiM2iT70C20=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VgToqUG21KKWIalRyqqVwDwii4BZKCrif92Rf6Vcoo/LVH7MFLLcPKgEPe0ClmYvt 61O1I5K5U4TkLJYtOiAwGuneWK1wjtQTXm/CR6MfoWv1L8vk2c9jr1R0kf/tjVzc1G DMvWJNib0GJD3f7TWMJDGKhZ3cPX8ipLc/pP2WQuRX/9xru5y1ua6XigDjfbfnHQo+ JLDPh+Tqn6R7vwGpASyzbQA15Cae5ecvCVKJBSf6Y1oFHLpqi/OdBG3iAxiBAAUxPU Jj0MdUHr/CHI4/THO3ITjF1S7ZTqWrpiJxd/VGYvIOxclv7LUrCLcy6daSnw+Ix8wr qs6iKAiihghCQ== From: Sasha Levin To: patches@lists.linux.dev Cc: Eric Dumazet , Simon Horman , Fernando Fernandez Mancera , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.1 227/232] ipv6: fix a race in ip6_sock_set_v6only() Date: Sat, 28 Feb 2026 13:11:20 -0500 Message-ID: <20260228181127.1592657-227-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228181127.1592657-1-sashal@kernel.org> References: <20260228181127.1592657-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Eric Dumazet [ Upstream commit 452a3eee22c57a5786ae6db5c97f3b0ec13bb3b7 ] It is unlikely that this function will be ever called with isk->inet_num being not zero. Perform the check on isk->inet_num inside the locked section for complete safety. Fixes: 9b115749acb24 ("ipv6: add ip6_sock_set_v6only") Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman Reviewed-by: Fernando Fernandez Mancera Link: https://patch.msgid.link/20260216102202.3343588-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- include/net/ipv6.h | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/include/net/ipv6.h b/include/net/ipv6.h index 517bdae78614b..3bf743d601e1c 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -1255,12 +1255,15 @@ int ipv6_sock_mc_drop(struct sock *sk, int ifindex, static inline int ip6_sock_set_v6only(struct sock *sk) { - if (inet_sk(sk)->inet_num) - return -EINVAL; + int ret = 0; + lock_sock(sk); - sk->sk_ipv6only = true; + if (inet_sk(sk)->inet_num) + ret = -EINVAL; + else + sk->sk_ipv6only = true; release_sock(sk); - return 0; + return ret; } static inline void ip6_sock_set_recverr(struct sock *sk) -- 2.51.0