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 99C171A76A2; Tue, 30 Jul 2024 17:15:49 +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=1722359749; cv=none; b=BhU/LBMGXvhsAK0YT0Uz89NEHZowzz62FssjiJKyTsjAXUQzXmNPDR8CJaS71q8PIYr1BNtpD/d1T94QscggQLtdfGi99LrxxIavnS5x8E6uYijLeueuCu08pVpgl2sn+yuBq+h2abxRoJku40jPnG1NaLNGzo4pd/VRWr9hfbM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722359749; c=relaxed/simple; bh=ubgpjZGd6IqG6YR2ZMqDe1y3pyPFDQIyt7qCwJglV8A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bJLoShBVtTJxxw0rzQ5SaokTmD0dtCWuBPyu2Pmg0KfKBpV0R2BZM+aDgHAyAytE1iKAYCeKxQMv4qX2ReCjxYr81hRf/OSlAwU+CeLzRSk5kH4gjLBE7R4UGwjjfhjCCt3+lM5MgtXq61klCJNiU3gXScEAQTg+fYawbre6Xm4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=N38a3GL1; 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="N38a3GL1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2072CC32782; Tue, 30 Jul 2024 17:15:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1722359749; bh=ubgpjZGd6IqG6YR2ZMqDe1y3pyPFDQIyt7qCwJglV8A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N38a3GL1TFiXsFnTnq2K6IDeWHGvzqrk9MgbjCoKA/7YDCZT7gzymYkQ4vfpWfoyx WprTbtxyexfCn71ywj8Er5HuaZF+dIqJgBWWX0tUaI2CJVssFK9eSbhmWfEHqjkuZm fisNaC93mYQeDUtIVbYVy3C6uAJMYShhF+rf32YU= 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 6.6 531/568] af_unix: Disable MSG_OOB handling for sockets in sockmap/sockhash Date: Tue, 30 Jul 2024 17:50:38 +0200 Message-ID: <20240730151700.910318052@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240730151639.792277039@linuxfoundation.org> References: <20240730151639.792277039@linuxfoundation.org> User-Agent: quilt/0.67 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 6.6-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 5a26e785ce70d..a551be47cb6c6 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2624,10 +2624,49 @@ 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