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 9BE3F1DE3B8; Wed, 6 Nov 2024 12:32:26 +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=1730896346; cv=none; b=DzouP7NKNWMnyqChLo2dWE91pm72ojPkuSgKXnM+eY6PbCFG2iT0rHFDTcvps6QkQZ5fghjv0McharcZdPpUz3t6FElAvNe4b494NmHWit1fSuPbjZ0kseOeXhtVgSUQFNj/DeG06Eq25wAhKf8uX2iLnHdgGyLxxvOkuWBtayA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730896346; c=relaxed/simple; bh=UeZrigwor1AVJXJn68Y8/b57siSAy7+pEkKdN0MNTB0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uzdtBAQNXetLZfctARopDf5iuNg6G1Gt7eo7L0HPq1cofVn4FcZYS6j6UN8wbFDYBrepj6MscTZKhx1lmFnCCGgaf+AYBHaBTXG0JOSX8HHcxwGdg5/B0DG4KS56CRJz+Rhhs5Vb8WNYgdxdyX5ONBJjb5Mym9YLShrK6QBPRvQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=znscjzMP; 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="znscjzMP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 254F6C4CECD; Wed, 6 Nov 2024 12:32:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730896346; bh=UeZrigwor1AVJXJn68Y8/b57siSAy7+pEkKdN0MNTB0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=znscjzMPfgISyFZkahipfZxa3yafJq6sQMIBEbb7bWR9N+1C5Yth/kW8bWJE6Ffi1 kG/ocD9mtfTnkFPohFnbJ8wrP8bhTbfEV2QI5ypI7vqRlSCru9uLArEEVgklSjhM4x 5WlMfPx8KgU/9QM/7lQzjNVf88ihOq+g0YT8FCUA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Geliang Tang , "Matthieu Baerts (NGI0)" , Simon Horman , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.11 172/245] mptcp: init: protect sched with rcu_read_lock Date: Wed, 6 Nov 2024 13:03:45 +0100 Message-ID: <20241106120323.472489384@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241106120319.234238499@linuxfoundation.org> References: <20241106120319.234238499@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 6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matthieu Baerts (NGI0) [ Upstream commit 3deb12c788c385e17142ce6ec50f769852fcec65 ] Enabling CONFIG_PROVE_RCU_LIST with its dependence CONFIG_RCU_EXPERT creates this splat when an MPTCP socket is created: ============================= WARNING: suspicious RCU usage 6.12.0-rc2+ #11 Not tainted ----------------------------- net/mptcp/sched.c:44 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 no locks held by mptcp_connect/176. stack backtrace: CPU: 0 UID: 0 PID: 176 Comm: mptcp_connect Not tainted 6.12.0-rc2+ #11 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: dump_stack_lvl (lib/dump_stack.c:123) lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) mptcp_sched_find (net/mptcp/sched.c:44 (discriminator 7)) mptcp_init_sock (net/mptcp/protocol.c:2867 (discriminator 1)) ? sock_init_data_uid (arch/x86/include/asm/atomic.h:28) inet_create.part.0.constprop.0 (net/ipv4/af_inet.c:386) ? __sock_create (include/linux/rcupdate.h:347 (discriminator 1)) __sock_create (net/socket.c:1576) __sys_socket (net/socket.c:1671) ? __pfx___sys_socket (net/socket.c:1712) ? do_user_addr_fault (arch/x86/mm/fault.c:1419 (discriminator 1)) __x64_sys_socket (net/socket.c:1728) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) That's because when the socket is initialised, rcu_read_lock() is not used despite the explicit comment written above the declaration of mptcp_sched_find() in sched.c. Adding the missing lock/unlock avoids the warning. Fixes: 1730b2b2c5a5 ("mptcp: add sched in mptcp_sock") Cc: stable@vger.kernel.org Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/523 Reviewed-by: Geliang Tang Signed-off-by: Matthieu Baerts (NGI0) Reviewed-by: Simon Horman Link: https://patch.msgid.link/20241021-net-mptcp-sched-lock-v1-1-637759cf061c@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/mptcp/protocol.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index d4b3bc46cdaaf..ec87b36f0d451 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2864,8 +2864,10 @@ static int mptcp_init_sock(struct sock *sk) if (unlikely(!net->mib.mptcp_statistics) && !mptcp_mib_alloc(net)) return -ENOMEM; + rcu_read_lock(); ret = mptcp_init_sched(mptcp_sk(sk), mptcp_sched_find(mptcp_get_scheduler(net))); + rcu_read_unlock(); if (ret) return ret; -- 2.43.0