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 65290184549; Tue, 30 Jul 2024 16:56:48 +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=1722358608; cv=none; b=Uw79jPvGAnpVuQ0qBklkiL0D8HtpD3nbeTb5bBQqRJdNCbeaT76+0+7pd5GYOv+AIQVtsstaUtQLxE1zJJ+Jk/K9IWTtpRPsaRCVP7GwY2KM/7XdbWhquntDV5KmJUY7edHICFoNRdTNW8GErZm69PpcgJLM3hJtNcmx+steEng= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722358608; c=relaxed/simple; bh=pL7ZAIs+TFJcVewFuOzADS6MncS9bacZVb52YYEqAlc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bbpBdhrdaNnYlKMP7Ksy8rQ4NPyodzdIlPFv96ujLkgUmcyHv20I1FxqwK/hxet0o1NK44MvyD5bdnLP4Dy9122YwD4EbLR6wRGcUaD1nUrjs04mV+9JOaz+FGY78NyT1NI18eYM5IpJJGz3Isa/UgZs4PG6Brtew0YG6gE2RIQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=aJD+WiB2; 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="aJD+WiB2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1467C32782; Tue, 30 Jul 2024 16:56:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1722358608; bh=pL7ZAIs+TFJcVewFuOzADS6MncS9bacZVb52YYEqAlc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aJD+WiB2w6LHGt/DVJHrSRZYWAh0LPkKghpf+5wDZ3xpP2hMWqVHyCGRPNI6NCFfJ wxeiI2o89enEpdmufydOAlZuhU2Z52YvJVr2vqBZgMC8VRax7vOvHjxv5+r25kpo0V V+NEOhsrsbBoHDk08jqbEHXvTJe+1ug8jUZMcI3I= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kuniyuki Iwashima , Michal Luczaj , Daniel Borkmann , Jakub Sitnicki , Sasha Levin Subject: [PATCH 6.1 406/440] af_unix: Disable MSG_OOB handling for sockets in sockmap/sockhash Date: Tue, 30 Jul 2024 17:50:39 +0200 Message-ID: <20240730151631.654731237@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240730151615.753688326@linuxfoundation.org> References: <20240730151615.753688326@linuxfoundation.org> User-Agent: quilt/0.67 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: Michal Luczaj [ Upstream commit 638f32604385fd23059985da8de918e9c18f0b98 ] AF_UNIX socket tracks the most recent OOB packet (in its receive queue) with an `oob_skb` pointer. BPF redirecting does not account for that: when an OOB packet is moved between sockets, `oob_skb` is left outdated. This results in a single skb that may be accessed from two different sockets. Take the easy way out: silently drop MSG_OOB data targeting any socket that is in a sockmap or a sockhash. Note that such silent drop is akin to the fate of redirected skb's scm_fp_list (SCM_RIGHTS, SCM_CREDENTIALS). For symmetry, forbid MSG_OOB in unix_bpf_recvmsg(). Fixes: 314001f0bf92 ("af_unix: Add OOB support") Suggested-by: Kuniyuki Iwashima Signed-off-by: Michal Luczaj Signed-off-by: Daniel Borkmann Tested-by: Jakub Sitnicki Reviewed-by: Kuniyuki Iwashima Reviewed-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20240713200218.2140950-2-mhal@rbox.co Signed-off-by: Sasha Levin --- net/unix/af_unix.c | 41 ++++++++++++++++++++++++++++++++++++++++- net/unix/unix_bpf.c | 3 +++ 2 files changed, 43 insertions(+), 1 deletion(-) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 3905cdcaa5184..db71f35b67b86 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2710,10 +2710,49 @@ static struct sk_buff *manage_oob(struct sk_buff *skb, struct sock *sk, static int unix_stream_read_skb(struct sock *sk, skb_read_actor_t recv_actor) { + struct unix_sock *u = unix_sk(sk); + struct sk_buff *skb; + int err; + if (unlikely(READ_ONCE(sk->sk_state) != TCP_ESTABLISHED)) return -ENOTCONN; - return unix_read_skb(sk, recv_actor); + mutex_lock(&u->iolock); + skb = skb_recv_datagram(sk, MSG_DONTWAIT, &err); + mutex_unlock(&u->iolock); + if (!skb) + return err; + +#if IS_ENABLED(CONFIG_AF_UNIX_OOB) + if (unlikely(skb == READ_ONCE(u->oob_skb))) { + bool drop = false; + + unix_state_lock(sk); + + if (sock_flag(sk, SOCK_DEAD)) { + unix_state_unlock(sk); + kfree_skb(skb); + return -ECONNRESET; + } + + spin_lock(&sk->sk_receive_queue.lock); + if (likely(skb == u->oob_skb)) { + WRITE_ONCE(u->oob_skb, NULL); + drop = true; + } + spin_unlock(&sk->sk_receive_queue.lock); + + unix_state_unlock(sk); + + if (drop) { + WARN_ON_ONCE(skb_unref(skb)); + kfree_skb(skb); + return -EAGAIN; + } + } +#endif + + return recv_actor(sk, skb); } static int unix_stream_read_generic(struct unix_stream_read_state *state, diff --git a/net/unix/unix_bpf.c b/net/unix/unix_bpf.c index bd84785bf8d6c..bca2d86ba97d8 100644 --- a/net/unix/unix_bpf.c +++ b/net/unix/unix_bpf.c @@ -54,6 +54,9 @@ static int unix_bpf_recvmsg(struct sock *sk, struct msghdr *msg, struct sk_psock *psock; int copied; + if (flags & MSG_OOB) + return -EOPNOTSUPP; + if (!len) return 0; -- 2.43.0