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 B443342847F; Tue, 16 Jun 2026 15:53:19 +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=1781625200; cv=none; b=uxPdSe+ZdIHKTRyBGOo9cuOzofeFOGrnrOA7jn61omiaxmTeQdu51I2KOcBUBT8Lv2KvaDk9ctcgHJ1NLU4mMEhnIswUYi3TGkuaDc0l8SYiExfWeSltkueJXn4jTlXBRYk1xLM8ErpMEZzFod4Rw7Jxm0Yc7ZALwtG1svT015I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781625200; c=relaxed/simple; bh=lOHOxH6UXht5Gt2Z0Oyrbz7iJcOnL6x43Jyeoh2IsXU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CHyBC0+BAZodA59aG0uTtdslPPeNTNmgkCqpjzuFFpOxVR+htws55jFz4mfONf57GYlamglfhySZ+1Am3MSAN0DCComFdHOn9+Q7mkTDc6B04zuEgAHEL9B04yZKn7ZbV5MJQRLHdfQt8H231PlZdyAeP6XKBVyJWFD7QcSA7pQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cuKXBUqz; 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="cuKXBUqz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74FBE1F000E9; Tue, 16 Jun 2026 15:53:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781625199; bh=yjcZv062jBe2DysJ1qCr+cHCs2MkFsb2jbyQmNqRRlw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=cuKXBUqzaNzHw51QYlfrZprozKVBPX8S8/7ypFKiJyG5rIgrv+4WrVNmpBP643ny2 qtYws9WNN8N9iP9iHlvvfAqsK/3HNBbYzwtZ0OVxZvyiS1NV6Bko4gHU8Uu7G2VUdX i/V4hn/d9vIr2C2fsT3SsaK9nGnsh6wMIzHvj+Ic= 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 6.18 097/325] tcp: restrict SO_ATTACH_FILTER to priv users Date: Tue, 16 Jun 2026 20:28:13 +0530 Message-ID: <20260616145102.521142898@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145057.827196531@linuxfoundation.org> References: <20260616145057.827196531@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 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 82470f59fa5c50..04fa0c18adc3e4 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1457,6 +1457,11 @@ 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