From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 280A3C433E3 for ; Mon, 29 Jun 2020 20:28:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 07B242067D for ; Mon, 29 Jun 2020 20:28:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593462522; bh=GCkqleTIEhxEzAjHTLKTxRSJhFEfrTPKKaxHOCz7VVY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0UJxDxH2SEjGKPlAWgqIf/gEQyU9eFV23NcnS2EomrLiC9J+9cQX8ab8d7Z95jSox ChRHI8vkYuTqfod3i79Np9MqxrOTvoy2Bu02SF4w+Vu6esMhNG4XWDnuU7ORmABNcn Tbaui8l4nYEH0BAFGy890ANaOmrPd9rFELHcPBrg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389190AbgF2U2k (ORCPT ); Mon, 29 Jun 2020 16:28:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:37022 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732498AbgF2TZX (ORCPT ); Mon, 29 Jun 2020 15:25:23 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 223C42542D; Mon, 29 Jun 2020 15:43:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593445382; bh=GCkqleTIEhxEzAjHTLKTxRSJhFEfrTPKKaxHOCz7VVY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g1n5GqRtWOivXOd2iKMdzuNpjeNYS9RK2TjrR+A2Pqgsw0UFPUL2u3EPZPe+6E7z/ gBvN7ks79/TYjnMOm2UYV/Sx60G5osydmYn4kkM2B8KW14naeSBOf73zBYEKLiWac2 N1n7TolSbMKDpYKnFrV8JcDkjjo/X/h/RfyOH2z0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Howells , syzbot+d3eccef36ddbd02713e9@syzkaller.appspotmail.com, "David S . Miller" , Greg Kroah-Hartman Subject: [PATCH 4.9 136/191] rxrpc: Fix notification call on completion of discarded calls Date: Mon, 29 Jun 2020 11:39:12 -0400 Message-Id: <20200629154007.2495120-137-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200629154007.2495120-1-sashal@kernel.org> References: <20200629154007.2495120-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.229-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.9.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.9.229-rc1 X-KernelTest-Deadline: 2020-07-01T15:39+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: David Howells [ Upstream commit 0041cd5a50442db6e456b145892a0eaf2dff061f ] When preallocated service calls are being discarded, they're passed to ->discard_new_call() to have the caller clean up any attached higher-layer preallocated pieces before being marked completed. However, the act of marking them completed now invokes the call's notification function - which causes a problem because that function might assume that the previously freed pieces of memory are still there. Fix this by setting a dummy notification function on the socket after calling ->discard_new_call(). This results in the following kasan message when the kafs module is removed. ================================================================== BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 fs/afs/rxrpc.c:707 Write of size 1 at addr ffff8880946c39e4 by task kworker/u4:1/21 CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.8.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 afs_wake_up_async_call+0x6aa/0x770 fs/afs/rxrpc.c:707 rxrpc_notify_socket+0x1db/0x5d0 net/rxrpc/recvmsg.c:40 __rxrpc_set_call_completion.part.0+0x172/0x410 net/rxrpc/recvmsg.c:76 __rxrpc_call_completed net/rxrpc/recvmsg.c:112 [inline] rxrpc_call_completed+0xca/0xf0 net/rxrpc/recvmsg.c:111 rxrpc_discard_prealloc+0x781/0xab0 net/rxrpc/call_accept.c:233 rxrpc_listen+0x147/0x360 net/rxrpc/af_rxrpc.c:245 afs_close_socket+0x95/0x320 fs/afs/rxrpc.c:110 afs_net_exit+0x1bc/0x310 fs/afs/main.c:155 ops_exit_list.isra.0+0xa8/0x150 net/core/net_namespace.c:186 cleanup_net+0x511/0xa50 net/core/net_namespace.c:603 process_one_work+0x965/0x1690 kernel/workqueue.c:2269 worker_thread+0x96/0xe10 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Allocated by task 6820: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:494 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:467 kmem_cache_alloc_trace+0x153/0x7d0 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] afs_alloc_call+0x55/0x630 fs/afs/rxrpc.c:141 afs_charge_preallocation+0xe9/0x2d0 fs/afs/rxrpc.c:757 afs_open_socket+0x292/0x360 fs/afs/rxrpc.c:92 afs_net_init+0xa6c/0xe30 fs/afs/main.c:125 ops_init+0xaf/0x420 net/core/net_namespace.c:151 setup_net+0x2de/0x860 net/core/net_namespace.c:341 copy_net_ns+0x293/0x590 net/core/net_namespace.c:482 create_new_namespaces+0x3fb/0xb30 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:231 ksys_unshare+0x43d/0x8e0 kernel/fork.c:2983 __do_sys_unshare kernel/fork.c:3051 [inline] __se_sys_unshare kernel/fork.c:3049 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3049 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 21: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 afs_put_call+0x585/0xa40 fs/afs/rxrpc.c:190 rxrpc_discard_prealloc+0x764/0xab0 net/rxrpc/call_accept.c:230 rxrpc_listen+0x147/0x360 net/rxrpc/af_rxrpc.c:245 afs_close_socket+0x95/0x320 fs/afs/rxrpc.c:110 afs_net_exit+0x1bc/0x310 fs/afs/main.c:155 ops_exit_list.isra.0+0xa8/0x150 net/core/net_namespace.c:186 cleanup_net+0x511/0xa50 net/core/net_namespace.c:603 process_one_work+0x965/0x1690 kernel/workqueue.c:2269 worker_thread+0x96/0xe10 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff8880946c3800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 484 bytes inside of 1024-byte region [ffff8880946c3800, ffff8880946c3c00) The buggy address belongs to the page: page:ffffea000251b0c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002546508 ffffea00024fa248 ffff8880aa000c40 raw: 0000000000000000 ffff8880946c3000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880946c3880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880946c3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880946c3980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880946c3a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880946c3a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Reported-by: syzbot+d3eccef36ddbd02713e9@syzkaller.appspotmail.com Fixes: 5ac0d62226a0 ("rxrpc: Fix missing notification") Signed-off-by: David Howells Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/rxrpc/call_accept.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c index 832d854c2d5c4..01ad588144e32 100644 --- a/net/rxrpc/call_accept.c +++ b/net/rxrpc/call_accept.c @@ -26,6 +26,11 @@ #include #include "ar-internal.h" +static void rxrpc_dummy_notify(struct sock *sk, struct rxrpc_call *call, + unsigned long user_call_ID) +{ +} + /* * Preallocate a single service call, connection and peer and, if possible, * give them a user ID and attach the user's side of the ID to them. @@ -224,6 +229,8 @@ void rxrpc_discard_prealloc(struct rxrpc_sock *rx) if (rx->discard_new_call) { _debug("discard %lx", call->user_call_ID); rx->discard_new_call(call, call->user_call_ID); + if (call->notify_rx) + call->notify_rx = rxrpc_dummy_notify; rxrpc_put_call(call, rxrpc_call_put_kernel); } rxrpc_call_completed(call); -- 2.25.1