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 C79C339B974 for ; Sat, 28 Feb 2026 18:17:20 +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=1772302640; cv=none; b=QRUSuLecjftT8EbK/PmAZjGvbjD+EyvRsLMmc9kc6gUOqeDWvcW5iJIk1OdagMpuwhpqZFaIilppCTKqiBW/GatO9nt+sYxFMFtjI25JAbBzvEmQoq7miYvO6h5BUNfv0EvjyyIGqdsGS280J89cx2akyRLrVV1qd2WG6t8J7o4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302640; c=relaxed/simple; bh=NN7nGb1beWUZXDlqn/i0aTeQYrzpcWrf9NS9gW+PTDQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aW2i4K4Ls0NzXDY5nCKbs+7tlxLxvLbNjTQKprdq6i2hZfyE0AFYKpnn8WiSk41b/GsdvMbiJ4sm3VZEEML3Ura8KIvRxVr59Q8zdZx4qC6B7j7N2Sf4SZvw6X9td4Toz/c8bjzOV/AL3RY7YvEQJqmGrESij5IvdPhNhYZr/wM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hRG9GhJP; 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="hRG9GhJP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A67CC19425; Sat, 28 Feb 2026 18:17:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772302640; bh=NN7nGb1beWUZXDlqn/i0aTeQYrzpcWrf9NS9gW+PTDQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hRG9GhJP5T8kboQKjzTAo1hXfo5/jIWU8wJZSMy6zujjt3YlamHy8Vid15uNHa3xV MxXu4RVt8bUZlVGxO033kPN/ndT6UfDZSoYyCC8bBKAcFsDLfWyx+LnTpXcBqkEvzG poRGp7Ih/Q/WGGWzJuyKJqzlC1umuIkN/oPDInZUFosYievauRzwFthP++k62sE2gY SQGTHBPLXVFLux+hPMYrc6aglkmk8hBysuXRyXq0HLeigwrrFr0OEUY9aIq39iyRjD J6mBFL3IxhAR4HrZwP6SlexO8k43KZi0I8q/xy79NUu6RreIZdjaJqNx9qLvB/kgBL T+IUbfBphCaBg== From: Sasha Levin To: patches@lists.linux.dev Cc: Eric Dumazet , Simon Horman , Fernando Fernandez Mancera , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 162/164] ipv6: fix a race in ip6_sock_set_v6only() Date: Sat, 28 Feb 2026 13:15:01 -0500 Message-ID: <20260228181505.1600663-162-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228181505.1600663-1-sashal@kernel.org> References: <20260228181505.1600663-1-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 608943944ce1a..dcae37154d3c2 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -1186,12 +1186,15 @@ 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