From patchwork Tue Apr 9 22:52:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 13623291 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp-fw-6001.amazon.com (smtp-fw-6001.amazon.com [52.95.48.154]) (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 D0659158D8F for ; Tue, 9 Apr 2024 22:53:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=52.95.48.154 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712703202; cv=none; b=ZN0EuiyqdOVr/QOYgNzW6cP8pPGe6KpKmJHit21PJxtNEQLv2VGjqh0fF48JtIsXwPTg02NDOegybhWIc5EsM+eIPlWYifauz0g5g3pEj+BxRWNglOtELz9f4zX6Om35fAscWckGDj7QHEcondZO2wx46TlTJrSy+1sAY5htmyg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712703202; c=relaxed/simple; bh=/mFzy0/wXcNdV8jrPyJzMG4utX210cUFx+M2IVusYww=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=seEKh3GQWWXBlYcF7XdDUcjImCQHYx9HWARQFB9clkJkdh+10PswFPnZSelfEW7z8d3XFvWmB5DH2FQZ31Qid5Il/TNmW/RhNTG410Go7xOO0E+xSkPSUIudMrxIAqwHf+2fvO/itmRhZ0Qscoov3LLREMlLF+2G3SRsF5A0rQI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.co.jp; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b=TdJHTEAY; arc=none smtp.client-ip=52.95.48.154 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.co.jp Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="TdJHTEAY" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1712703201; x=1744239201; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=PVdZPzfe9EF/CBelLXYDz0AmXvtZb+wa+Sc+QCYcmCs=; b=TdJHTEAY8+e7PChG73v5ls07sQ1pXec1VT2oeyIPLqPd9C6SoQYZGluk giSILAX5C+6fNfHEugiC1tXXUrS7d4t0HidyUQtVqP4WRQ1VqG+Q28W4V hpVcYSFJUaiGbMDA2DxyCgpRHtrrvGsEGM4Nh8Xqr3bOQQ8FgTL2hUrys 0=; X-IronPort-AV: E=Sophos;i="6.07,190,1708387200"; d="scan'208";a="388632866" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO smtpout.prod.us-east-1.prod.farcaster.email.amazon.dev) ([10.43.8.2]) by smtp-border-fw-6001.iad6.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Apr 2024 22:53:20 +0000 Received: from EX19MTAUWA001.ant.amazon.com [10.0.38.20:29104] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.12.255:2525] with esmtp (Farcaster) id 37762a40-b759-423a-8c09-16996039ac07; Tue, 9 Apr 2024 22:53:19 +0000 (UTC) X-Farcaster-Flow-ID: 37762a40-b759-423a-8c09-16996039ac07 Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX19MTAUWA001.ant.amazon.com (10.250.64.217) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.28; Tue, 9 Apr 2024 22:53:18 +0000 Received: from 88665a182662.ant.amazon.com (10.106.100.45) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.28; Tue, 9 Apr 2024 22:53:15 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni CC: Rao shoaib , Kuniyuki Iwashima , Kuniyuki Iwashima , Subject: [PATCH v1 net 2/3] af_unix: Don't peek OOB data without MSG_OOB. Date: Tue, 9 Apr 2024 15:52:08 -0700 Message-ID: <20240409225209.58102-3-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20240409225209.58102-1-kuniyu@amazon.com> References: <20240409225209.58102-1-kuniyu@amazon.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: EX19D035UWB003.ant.amazon.com (10.13.138.85) To EX19D004ANA001.ant.amazon.com (10.37.240.138) X-Patchwork-Delegate: kuba@kernel.org Currently, we can read OOB data without MSG_OOB by using MSG_PEEK when OOB data is sitting on the front row, which is apparently wrong. >>> from socket import * >>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM) >>> c1.send(b'a', MSG_OOB) 1 >>> c2.recv(1, MSG_PEEK | MSG_DONTWAIT) b'a' If manage_oob() is called when no data has been copied, we only check if the socket enables SO_OOBINLINE or MSG_PEEK is not used. Otherwise, the skb is returned as is. However, here we should return NULL if MSG_PEEK is set and no data has been copied. Also, in such a case, we should not jump to the redo label because we will be caught in the loop and hog the CPU until normal data comes in. Then, we need to handle skb == NULL case with the if-clause below the manage_oob() block. With this patch: >>> from socket import * >>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM) >>> c1.send(b'a', MSG_OOB) 1 >>> c2.recv(1, MSG_PEEK | MSG_DONTWAIT) Traceback (most recent call last): File "", line 1, in BlockingIOError: [Errno 11] Resource temporarily unavailable Fixes: 314001f0bf92 ("af_unix: Add OOB support") Signed-off-by: Kuniyuki Iwashima --- net/unix/af_unix.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index f297320438bf..9a6ad5974dff 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2663,7 +2663,9 @@ static struct sk_buff *manage_oob(struct sk_buff *skb, struct sock *sk, WRITE_ONCE(u->oob_skb, NULL); consume_skb(skb); } - } else if (!(flags & MSG_PEEK)) { + } else if (flags & MSG_PEEK) { + skb = NULL; + } else { skb_unlink(skb, &sk->sk_receive_queue); WRITE_ONCE(u->oob_skb, NULL); if (!WARN_ON_ONCE(skb_unref(skb))) @@ -2745,11 +2747,9 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state, #if IS_ENABLED(CONFIG_AF_UNIX_OOB) if (skb) { skb = manage_oob(skb, sk, flags, copied); - if (!skb) { + if (!skb && copied) { unix_state_unlock(sk); - if (copied) - break; - goto redo; + break; } } #endif