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 9A02D2D3EEE; Wed, 25 Feb 2026 06:58:51 +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=1772002731; cv=none; b=Zb0NOwyRpXiW31GXs1inMDdAg8OrNh56K7QBBsKczHrbm2zZP9XA+B0TwK+u4UhnnsWyMal0/EbktzAY8QnBU7tkP2pgMENzyEFflBVH4vlmQx9voIRVwe1b9mBaVSePw84rx5Q5vlYUtKIrUkHdbKvTxDLZpilpn8vGBPHasAc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772002731; c=relaxed/simple; bh=/m49pow1O/4IvwKoVrJWPny6owwv9SzJE9kXCvOEX/g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hwHIpVnIGdpSkfXSoh/QS4esICd7dKW/mev5KAQ/aNy/pMqnnqZNjZwWzeWhyRvmwXDDydoXNnUGtuWae2jEPdDmWF7xT6kGoUz2GvPz1DR5q3stOtQhyc73oxn0uvGyA1hh2d7LHaDJKxY7pmVoMarOeKP3DpDIRWfPOtp/zuQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hPl07Eo1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hPl07Eo1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7093CC116D0; Wed, 25 Feb 2026 06:58:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1772002731; bh=/m49pow1O/4IvwKoVrJWPny6owwv9SzJE9kXCvOEX/g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hPl07Eo1QY+SWycMOni75+WjSNXIxUx08QpEiYx+niABMSf5oljudlXLVRzVaASNV GIB6ijT+ttcwgi1YRWIGjtiq8fXpUeyN/T+VDRViyxOM2g49ZBDjkmrxhv68TN49vv gxIGdheeNbjGb2VA4Ug9/CzXhaik5/tv39VLYb0E= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Simon Horman , Fernando Fernandez Mancera , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 545/641] ipv6: fix a race in ip6_sock_set_v6only() Date: Tue, 24 Feb 2026 17:24:31 -0800 Message-ID: <20260225012401.734981618@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260225012348.915798704@linuxfoundation.org> References: <20260225012348.915798704@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ 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 2ccdf85f34f16..f0936df7567e3 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -1280,12 +1280,15 @@ 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