From patchwork Thu Apr 14 13:13:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 561549 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1EFB9C41535 for ; Thu, 14 Apr 2022 14:11:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245697AbiDNOI2 (ORCPT ); Thu, 14 Apr 2022 10:08:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42010 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347697AbiDNN72 (ORCPT ); Thu, 14 Apr 2022 09:59:28 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1D5CFB898A; Thu, 14 Apr 2022 06:51:36 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id CCCEEB82985; Thu, 14 Apr 2022 13:51:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43E5AC385A5; Thu, 14 Apr 2022 13:51:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649944293; bh=IExYXdTxHpkDpniovkL4rx+wxWfCuzt7QxTt5uIifi0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PTHNNNfkV8QfpymjQhOmX4vcjVySl9zGXQdT8swc4cK1Y8uG0rlf7oDeRc9LS8gMh MM9PissnFPVdlyGjwp5dAeNDkjmtwltEcyOV5VW9GGZH9fDSSDmVf4CwBufI6LqwgF gTf1t/7Kdv/l4OfkjybTs/WzvTI6J5QxUpaOL/BI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , David Howells , Marc Dionne , linux-afs@lists.infradead.org, syzbot , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 436/475] rxrpc: fix a race in rxrpc_exit_net() Date: Thu, 14 Apr 2022 15:13:41 +0200 Message-Id: <20220414110907.264322495@linuxfoundation.org> X-Mailer: git-send-email 2.35.2 In-Reply-To: <20220414110855.141582785@linuxfoundation.org> References: <20220414110855.141582785@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Dumazet [ Upstream commit 1946014ca3b19be9e485e780e862c375c6f98bad ] Current code can lead to the following race: CPU0 CPU1 rxrpc_exit_net() rxrpc_peer_keepalive_worker() if (rxnet->live) rxnet->live = false; del_timer_sync(&rxnet->peer_keepalive_timer); timer_reduce(&rxnet->peer_keepalive_timer, jiffies + delay); cancel_work_sync(&rxnet->peer_keepalive_work); rxrpc_exit_net() exits while peer_keepalive_timer is still armed, leading to use-after-free. syzbot report was: ODEBUG: free active (active state 0) object type: timer_list hint: rxrpc_peer_keepalive_timeout+0x0/0xb0 WARNING: CPU: 0 PID: 3660 at lib/debugobjects.c:505 debug_print_object+0x16e/0x250 lib/debugobjects.c:505 Modules linked in: CPU: 0 PID: 3660 Comm: kworker/u4:6 Not tainted 5.17.0-syzkaller-13993-g88e6c0207623 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:505 Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 af 00 00 00 48 8b 14 dd 00 1c 26 8a 4c 89 ee 48 c7 c7 00 10 26 8a e8 b1 e7 28 05 <0f> 0b 83 05 15 eb c5 09 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3 RSP: 0018:ffffc9000353fb00 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: ffff888029196140 RSI: ffffffff815efad8 RDI: fffff520006a7f52 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815ea4ae R11: 0000000000000000 R12: ffffffff89ce23e0 R13: ffffffff8a2614e0 R14: ffffffff816628c0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f2908924 CR3: 0000000043720000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __debug_check_no_obj_freed lib/debugobjects.c:992 [inline] debug_check_no_obj_freed+0x301/0x420 lib/debugobjects.c:1023 kfree+0xd6/0x310 mm/slab.c:3809 ops_free_list.part.0+0x119/0x370 net/core/net_namespace.c:176 ops_free_list net/core/net_namespace.c:174 [inline] cleanup_net+0x591/0xb00 net/core/net_namespace.c:598 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Fixes: ace45bec6d77 ("rxrpc: Fix firewall route keepalive") Signed-off-by: Eric Dumazet Cc: David Howells Cc: Marc Dionne Cc: linux-afs@lists.infradead.org Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/rxrpc/net_ns.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/rxrpc/net_ns.c b/net/rxrpc/net_ns.c index b312aab80fed..9a76b74af37b 100644 --- a/net/rxrpc/net_ns.c +++ b/net/rxrpc/net_ns.c @@ -116,8 +116,8 @@ static __net_exit void rxrpc_exit_net(struct net *net) struct rxrpc_net *rxnet = rxrpc_net(net); rxnet->live = false; - del_timer_sync(&rxnet->peer_keepalive_timer); cancel_work_sync(&rxnet->peer_keepalive_work); + del_timer_sync(&rxnet->peer_keepalive_timer); rxrpc_destroy_all_calls(rxnet); rxrpc_destroy_all_connections(rxnet); rxrpc_destroy_all_peers(rxnet);