From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 AEE6C44DB64; Tue, 16 Jun 2026 16:20:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781626825; cv=none; b=sUP9s3IpQXuFgL4ukLBFSsZOiu4YG7dXshCqKfbnv+65IbZByZbCgDNbGssg91TXhHz8MY1xkMxKNH5HrUh3H5iMAB685AErQqBA9p/8SnlaFwE/vIG9GfvZaBvZjnBQGRt0O03OKrfyyFFxkspzbOrd9aQIwcKUqNsvoJCF4WM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781626825; c=relaxed/simple; bh=GhaheBpkstUbwL/QXb0OOJVLFhSZ24ZZjfP8T209BlA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AVp8ihw89Szp9sAadkcIRTryet9iSKolbPn8C6rgiyJn+2Z7N0dcuAVvpa8BSaejFDeNE2idZPJPhsxYG5O+FwbUZj0rj3N/Ih4OMgkfVXqqEopAoeglqPScl/mws83GYbTpv33QPoub8G3brYgnEoIYa47yaE1xk78FeNXatkk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=y7LZALu5; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="y7LZALu5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10A8D1F000E9; Tue, 16 Jun 2026 16:20:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781626824; bh=AkkTVndk6vBfyKqcliCHNuoImqwDBSalwJWpkivIfm8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=y7LZALu5w/ebwIfKhGfDI6enSUyXlyow9q3SK4SssMytvurVJEzvv9MLizXitgV2l Jqcl+l4+9S//eChtEj9enNVWfDvEpakL3jR6uMcku4KTT+Som6E4SqB9C5E0DKefwE Wg+8/Rj4c2Ng18AKH2g0BBEc4Myj8ugoy/P4BVhE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Tamir Shahar , Amit Klein , Willem de Bruijn , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Kumar Kartikeya Dwivedi , Song Liu , Yonghong Song , Jiri Olsa , John Fastabend , Stanislav Fomichev , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12 078/261] tcp: restrict SO_ATTACH_FILTER to priv users Date: Tue, 16 Jun 2026 20:28:36 +0530 Message-ID: <20260616145048.700582604@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145044.869532709@linuxfoundation.org> References: <20260616145044.869532709@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 5d39580f68e6ddeedd15e587282207489dfb3da2 ] This patch restricts the use of SO_ATTACH_FILTER (cBPF) on TCP sockets to users with CAP_NET_ADMIN capability. This blocks potential side-channel attack where an unprivileged application attaches a filter to leak TCP sequence/acknowledgment numbers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: Tamir Shahar Reported-by: Amit Klein Cc: Willem de Bruijn Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Andrii Nakryiko Cc: Martin KaFai Lau Cc: Eduard Zingerman Cc: Kumar Kartikeya Dwivedi Cc: Song Liu Cc: Yonghong Song Cc: Jiri Olsa Cc: John Fastabend Cc: Stanislav Fomichev Acked-by: Daniel Borkmann Reviewed-by: Willem de Bruijn Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/core/sock.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/core/sock.c b/net/core/sock.c index 7b6ed7c85a58cc..4a09e780406fe8 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1455,6 +1455,11 @@ int sk_setsockopt(struct sock *sk, int level, int optname, case SO_ATTACH_FILTER: { struct sock_fprog fprog; + if (sk_is_tcp(sk) && + !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) { + ret = -EPERM; + break; + } ret = copy_bpf_fprog_from_user(&fprog, optval, optlen); if (!ret) ret = sk_attach_filter(&fprog, sk); -- 2.53.0