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 7314236C9C4 for ; Sat, 28 Feb 2026 18:11:04 +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=1772302264; cv=none; b=M8tmiaQeLkvB1vKCLlVVtswQ4ba1MW1HOMRDZtmK+tMfxm9kXa6gXgSXSojJjdIrEmjG5j9Y0VYKpys7cSmGulAZWTA72Qr5e7VSgJFQzAISQsTk+e9IceyOfPELoyLeGUrqzDRGim6letE6qWp5VZPNjF/0GtBcCaDWp13L4dM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302264; c=relaxed/simple; bh=mpvGAouRdmmEBeN2Pz5xiIAzZ+mdgAb7cJwdfl/OZIY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pza4q/zcnqDVwk2PeXJtRa9lYWfrVrXXELHHeMQeJOdVzNF3OZRyauwL16UbUrfee5EWC44xALyIXw1ow6AOR+nQAa+65y8HMNQBoD3JQ+rrOeG82PAaVEiFDFR3eZHR7rV4SuwRjBPJFL4EJ8tbsg2VPTAt4l9BIF64TRjQbiM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hDPfNNvU; 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="hDPfNNvU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEFB9C19423; Sat, 28 Feb 2026 18:11:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772302264; bh=mpvGAouRdmmEBeN2Pz5xiIAzZ+mdgAb7cJwdfl/OZIY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hDPfNNvUqspeJcXDcGMEFjF+8ZjI4NNfv12ZHvEHDl6zG110of2weWsuKU4sucVSE yC+q4giEz/d/t/0laFGcsauIgtgcxP278nlqEXtFobaj0qIr4Nt9qynDxGG4Ksf0Uq pP1oUwD2tPoVCUJsKSFlq4atL9OObT+i6kOiptP7gdrC1n4mDDlTKUpiseiYPtITgf NSNIA0eN1ZE988VVcUQjNIhJ3Az00/6oKOiJkk6Hoq4iOFaUFL9fDYX8iOTPHBh0gf XQB6hrotBoUVZh8MhHerFh5SgbaXpLNy1WTZ33R+7P+uHtq/hB6AZkiVkmKlha46Pp g1nZQ3eyqZzIA== From: Sasha Levin To: patches@lists.linux.dev Cc: Eric Dumazet , Simon Horman , Fernando Fernandez Mancera , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 280/283] ipv6: fix a race in ip6_sock_set_v6only() Date: Sat, 28 Feb 2026 13:07:02 -0500 Message-ID: <20260228180709.1583486-280-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228180709.1583486-1-sashal@kernel.org> References: <20260228180709.1583486-1-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 c6932d1a3fa80..9e5e44c6da0a6 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -1293,12 +1293,15 @@ 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