releases/4.9.169/net-rds-force-to-destroy-connection-if-t_sock-is-null-in-rds_tcp_kill_sock.patch

   1 From foo@baz Mon Apr 15 09:15:08 CEST 2019
   2 From: Mao Wenan <maowenan@huawei.com>
   3 Date: Thu, 28 Mar 2019 17:10:56 +0800
   4 Subject: net: rds: force to destroy connection if t_sock is NULL in rds_tcp_kill_sock().
   5
   6 From: Mao Wenan <maowenan@huawei.com>
   7
   8 [ Upstream commit cb66ddd156203daefb8d71158036b27b0e2caf63 ]
   9
  10 When it is to cleanup net namespace, rds_tcp_exit_net() will call
  11 rds_tcp_kill_sock(), if t_sock is NULL, it will not call
  12 rds_conn_destroy(), rds_conn_path_destroy() and rds_tcp_conn_free() to free
  13 connection, and the worker cp_conn_w is not stopped, afterwards the net is freed in
  14 net_drop_ns(); While cp_conn_w rds_connect_worker() will call rds_tcp_conn_path_connect()
  15 and reference 'net' which has already been freed.
  16
  17 In rds_tcp_conn_path_connect(), rds_tcp_set_callbacks() will set t_sock = sock before
  18 sock->ops->connect, but if connect() is failed, it will call
  19 rds_tcp_restore_callbacks() and set t_sock = NULL, if connect is always
  20 failed, rds_connect_worker() will try to reconnect all the time, so
  21 rds_tcp_kill_sock() will never to cancel worker cp_conn_w and free the
  22 connections.
  23
  24 Therefore, the condition !tc->t_sock is not needed if it is going to do
  25 cleanup_net->rds_tcp_exit_net->rds_tcp_kill_sock, because tc->t_sock is always
  26 NULL, and there is on other path to cancel cp_conn_w and free
  27 connection. So this patch is to fix this.
  28
  29 rds_tcp_kill_sock():
  30 ...
  31 if (net != c_net || !tc->t_sock)
  32 ...
  33 Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
  34
  35 ==================================================================
  36 BUG: KASAN: use-after-free in inet_create+0xbcc/0xd28
  37 net/ipv4/af_inet.c:340
  38 Read of size 4 at addr ffff8003496a4684 by task kworker/u8:4/3721
  39
  40 CPU: 3 PID: 3721 Comm: kworker/u8:4 Not tainted 5.1.0 #11
  41 Hardware name: linux,dummy-virt (DT)
  42 Workqueue: krdsd rds_connect_worker
  43 Call trace:
  44  dump_backtrace+0x0/0x3c0 arch/arm64/kernel/time.c:53
  45  show_stack+0x28/0x38 arch/arm64/kernel/traps.c:152
  46  __dump_stack lib/dump_stack.c:77 [inline]
  47  dump_stack+0x120/0x188 lib/dump_stack.c:113
  48  print_address_description+0x68/0x278 mm/kasan/report.c:253
  49  kasan_report_error mm/kasan/report.c:351 [inline]
  50  kasan_report+0x21c/0x348 mm/kasan/report.c:409
  51  __asan_report_load4_noabort+0x30/0x40 mm/kasan/report.c:429
  52  inet_create+0xbcc/0xd28 net/ipv4/af_inet.c:340
  53  __sock_create+0x4f8/0x770 net/socket.c:1276
  54  sock_create_kern+0x50/0x68 net/socket.c:1322
  55  rds_tcp_conn_path_connect+0x2b4/0x690 net/rds/tcp_connect.c:114
  56  rds_connect_worker+0x108/0x1d0 net/rds/threads.c:175
  57  process_one_work+0x6e8/0x1700 kernel/workqueue.c:2153
  58  worker_thread+0x3b0/0xdd0 kernel/workqueue.c:2296
  59  kthread+0x2f0/0x378 kernel/kthread.c:255
  60  ret_from_fork+0x10/0x18 arch/arm64/kernel/entry.S:1117
  61
  62 Allocated by task 687:
  63  save_stack mm/kasan/kasan.c:448 [inline]
  64  set_track mm/kasan/kasan.c:460 [inline]
  65  kasan_kmalloc+0xd4/0x180 mm/kasan/kasan.c:553
  66  kasan_slab_alloc+0x14/0x20 mm/kasan/kasan.c:490
  67  slab_post_alloc_hook mm/slab.h:444 [inline]
  68  slab_alloc_node mm/slub.c:2705 [inline]
  69  slab_alloc mm/slub.c:2713 [inline]
  70  kmem_cache_alloc+0x14c/0x388 mm/slub.c:2718
  71  kmem_cache_zalloc include/linux/slab.h:697 [inline]
  72  net_alloc net/core/net_namespace.c:384 [inline]
  73  copy_net_ns+0xc4/0x2d0 net/core/net_namespace.c:424
  74  create_new_namespaces+0x300/0x658 kernel/nsproxy.c:107
  75  unshare_nsproxy_namespaces+0xa0/0x198 kernel/nsproxy.c:206
  76  ksys_unshare+0x340/0x628 kernel/fork.c:2577
  77  __do_sys_unshare kernel/fork.c:2645 [inline]
  78  __se_sys_unshare kernel/fork.c:2643 [inline]
  79  __arm64_sys_unshare+0x38/0x58 kernel/fork.c:2643
  80  __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
  81  invoke_syscall arch/arm64/kernel/syscall.c:47 [inline]
  82  el0_svc_common+0x168/0x390 arch/arm64/kernel/syscall.c:83
  83  el0_svc_handler+0x60/0xd0 arch/arm64/kernel/syscall.c:129
  84  el0_svc+0x8/0xc arch/arm64/kernel/entry.S:960
  85
  86 Freed by task 264:
  87  save_stack mm/kasan/kasan.c:448 [inline]
  88  set_track mm/kasan/kasan.c:460 [inline]
  89  __kasan_slab_free+0x114/0x220 mm/kasan/kasan.c:521
  90  kasan_slab_free+0x10/0x18 mm/kasan/kasan.c:528
  91  slab_free_hook mm/slub.c:1370 [inline]
  92  slab_free_freelist_hook mm/slub.c:1397 [inline]
  93  slab_free mm/slub.c:2952 [inline]
  94  kmem_cache_free+0xb8/0x3a8 mm/slub.c:2968
  95  net_free net/core/net_namespace.c:400 [inline]
  96  net_drop_ns.part.6+0x78/0x90 net/core/net_namespace.c:407
  97  net_drop_ns net/core/net_namespace.c:406 [inline]
  98  cleanup_net+0x53c/0x6d8 net/core/net_namespace.c:569
  99  process_one_work+0x6e8/0x1700 kernel/workqueue.c:2153
 100  worker_thread+0x3b0/0xdd0 kernel/workqueue.c:2296
 101  kthread+0x2f0/0x378 kernel/kthread.c:255
 102  ret_from_fork+0x10/0x18 arch/arm64/kernel/entry.S:1117
 103
 104 The buggy address belongs to the object at ffff8003496a3f80
 105  which belongs to the cache net_namespace of size 7872
 106 The buggy address is located 1796 bytes inside of
 107  7872-byte region [ffff8003496a3f80, ffff8003496a5e40)
 108 The buggy address belongs to the page:
 109 page:ffff7e000d25a800 count:1 mapcount:0 mapping:ffff80036ce4b000
 110 index:0x0 compound_mapcount: 0
 111 flags: 0xffffe0000008100(slab|head)
 112 raw: 0ffffe0000008100 dead000000000100 dead000000000200 ffff80036ce4b000
 113 raw: 0000000000000000 0000000080040004 00000001ffffffff 0000000000000000
 114 page dumped because: kasan: bad access detected
 115
 116 Memory state around the buggy address:
 117  ffff8003496a4580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 118  ffff8003496a4600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 119 >ffff8003496a4680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 120                    ^
 121  ffff8003496a4700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 122  ffff8003496a4780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 123 ==================================================================
 124
 125 Fixes: 467fa15356ac("RDS-TCP: Support multiple RDS-TCP listen endpoints, one per netns.")
 126 Reported-by: Hulk Robot <hulkci@huawei.com>
 127 Signed-off-by: Mao Wenan <maowenan@huawei.com>
 128 Signed-off-by: David S. Miller <davem@davemloft.net>
 129 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 130 ---
 131  net/rds/tcp.c |    2 +-
 132  1 file changed, 1 insertion(+), 1 deletion(-)
 133
 134 --- a/net/rds/tcp.c
 135 +++ b/net/rds/tcp.c
 136 @@ -527,7 +527,7 @@ static void rds_tcp_kill_sock(struct net
 137         list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
 138                 struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net);
 139
 140 -               if (net != c_net || !tc->t_sock)
 141 +               if (net != c_net)
 142                         continue;
 143                 if (!list_has_conn(&tmp_list, tc->t_cpath->cp_conn)) {
 144                         list_move_tail(&tc->t_tcp_node, &tmp_list);