From mboxrd@z Thu Jan 1 00:00:00 1970 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 5443A4414; Thu, 3 Jul 2025 15:03:22 +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=1751555002; cv=none; b=C2Ioly6qbrpNAF+sTwvuWOCdADu63TdUmvA2kDZX2jR9O8Ig4F5XTt64hiCzv3vNBnUuJHxZa7kZcHc9Fq0186QqEDPHVRrkSE/kg5nMN94JX//snPF7xJxFiFtpkBy/kIkrEk8AznMGE55zO9luwdnNgw0s6Pq1K2htfacKtXk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751555002; c=relaxed/simple; bh=ssBR4HCDhHRq1Cu9a0HlZyNMBH1RTtPajxXKK1VuibQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Y7gMbnOL6dyEt7O/H5nFpAFuhd/ka8/rn2SSPDMPcSbO65I1mWoupVDXtROizwLXHpIPeD+VEfwp5iTT1g6JsCJYthiDTdrLS9AnMgdRqpfSnxjjgoDSe35W9BtZ/lYzGeSUoyY+iknV23F5LzKhgiZliCshFkrzaDm9eMHQjFs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=eQDA26rj; 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="eQDA26rj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5660C4CEE3; Thu, 3 Jul 2025 15:03:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1751555002; bh=ssBR4HCDhHRq1Cu9a0HlZyNMBH1RTtPajxXKK1VuibQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eQDA26rjaJfZrIjL0Bxm6XG0RCg5HgfD+r9VJHiizbrdHk6jM58S4rDE5hrmBWy2n jtGt+WQdpe6odFPyY91qatO4gjrBc5KHZ0DQwptivkONGIn9SN5Pwb7xqseDQMollP klJUHUvU6x59rlh40YbHXICthhQR/zTHmOCDQG44= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christian Brauner , Kuniyuki Iwashima , Paolo Abeni , Sasha Levin Subject: [PATCH 6.15 145/263] af_unix: Dont set -ECONNRESET for consumed OOB skb. Date: Thu, 3 Jul 2025 16:41:05 +0200 Message-ID: <20250703144010.169752144@linuxfoundation.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250703144004.276210867@linuxfoundation.org> References: <20250703144004.276210867@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kuniyuki Iwashima [ Upstream commit 2a5a4841846b079b5fca5752fe94e59346fbda40 ] Christian Brauner reported that even after MSG_OOB data is consumed, calling close() on the receiver socket causes the peer's recv() to return -ECONNRESET: 1. send() and recv() an OOB data. >>> from socket import * >>> s1, s2 = socketpair(AF_UNIX, SOCK_STREAM) >>> s1.send(b'x', MSG_OOB) 1 >>> s2.recv(1, MSG_OOB) b'x' 2. close() for s2 sets ECONNRESET to s1->sk_err even though s2 consumed the OOB data >>> s2.close() >>> s1.recv(10, MSG_DONTWAIT) ... ConnectionResetError: [Errno 104] Connection reset by peer Even after being consumed, the skb holding the OOB 1-byte data stays in the recv queue to mark the OOB boundary and break recv() at that point. This must be considered while close()ing a socket. Let's skip the leading consumed OOB skb while checking the -ECONNRESET condition in unix_release_sock(). Fixes: 314001f0bf92 ("af_unix: Add OOB support") Reported-by: Christian Brauner Closes: https://lore.kernel.org/netdev/20250529-sinkt-abfeuern-e7b08200c6b0@brauner/ Signed-off-by: Kuniyuki Iwashima Acked-by: Christian Brauner Link: https://patch.msgid.link/20250619041457.1132791-4-kuni1840@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/unix/af_unix.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index af003831f4c67..52f2812d2fa5b 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -654,6 +654,11 @@ static void unix_sock_destructor(struct sock *sk) #endif } +static unsigned int unix_skb_len(const struct sk_buff *skb) +{ + return skb->len - UNIXCB(skb).consumed; +} + static void unix_release_sock(struct sock *sk, int embrion) { struct unix_sock *u = unix_sk(sk); @@ -688,10 +693,16 @@ static void unix_release_sock(struct sock *sk, int embrion) if (skpair != NULL) { if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { + struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); + +#if IS_ENABLED(CONFIG_AF_UNIX_OOB) + if (skb && !unix_skb_len(skb)) + skb = skb_peek_next(skb, &sk->sk_receive_queue); +#endif unix_state_lock(skpair); /* No more writes */ WRITE_ONCE(skpair->sk_shutdown, SHUTDOWN_MASK); - if (!skb_queue_empty_lockless(&sk->sk_receive_queue) || embrion) + if (skb || embrion) WRITE_ONCE(skpair->sk_err, ECONNRESET); unix_state_unlock(skpair); skpair->sk_state_change(skpair); @@ -2578,11 +2589,6 @@ static long unix_stream_data_wait(struct sock *sk, long timeo, return timeo; } -static unsigned int unix_skb_len(const struct sk_buff *skb) -{ - return skb->len - UNIXCB(skb).consumed; -} - struct unix_stream_read_state { int (*recv_actor)(struct sk_buff *, int, int, struct unix_stream_read_state *); -- 2.39.5