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 6F8C23876CF; Tue, 16 Jun 2026 17:39:56 +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=1781631597; cv=none; b=EG+ypw0vKGw5Kmlkccvk0L196AfQtme3+k3cppTIALD4ZZfVAYut50yvm3qmjAlzOlALrRryjHjEeSYEMMqIBcCdiz5LZ6z8fve/FkSVVsbTW+ORBMS5A5eHxFHfmehi5W/5+djIEVflKvU8MPWr+nrBntmcIT9ea4q6OlIk3pw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781631597; c=relaxed/simple; bh=M85bzhLnLmkIKRX/wR7n19Gqoh3FSCnFrP/tVIBEwWc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=APRXzsYOnN50llsFfbNnJsJ5fStQRs/XzwkwPBIOqlHqprFsmURnfrTCczBwvEi6xVcRJIbRHX5Gf906G3e064Si14aSPQgr6CBb/qsIKaEbofQMmatJxgx697tvna/bLzc4ScaPCI4kuvZKSpQTY/oHvMFsb7PTv7wZGLlv3Us= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Zp1jFsYk; 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="Zp1jFsYk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC7C21F000E9; Tue, 16 Jun 2026 17:39:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781631596; bh=uVyo5MzyYcNcztjcwQW4Zhg8C6YvQP/GRxpYlrX7DZE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Zp1jFsYktzU/Pg0i8T3DYJCWR23iJpd6tt9QztNLIgK69LDE3zwKjEA9AN4dsARvw jiuZ0IOJDpV2cFYO+FW0pLkKVErBOJlBaI6UH+E+wUIT9RtFUyU0rIJgAncsIg5cUO 9YVfGiOV8ItdPWaw7bVNafuFmzMrSo2aroQrPQ1M= 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 6.1 243/522] tcp: restrict SO_ATTACH_FILTER to priv users Date: Tue, 16 Jun 2026 20:26:30 +0530 Message-ID: <20260616145137.349922250@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145125.307082728@linuxfoundation.org> References: <20260616145125.307082728@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 6.1-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 62411c8870e855..5f79f0b78321c8 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1294,6 +1294,11 @@ 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