target/linux/generic/backport-5.4/080-wireguard-0081-wireguard-allowedips-fix-use-after-free-in-root_remo.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Eric Dumazet <edumazet@google.com>
   3 Date: Tue, 4 Feb 2020 22:17:25 +0100
   4 Subject: [PATCH] wireguard: allowedips: fix use-after-free in
   5  root_remove_peer_lists
   6
   7 commit 9981159fc3b677b357f84e069a11de5a5ec8a2a8 upstream.
   8
   9 In the unlikely case a new node could not be allocated, we need to
  10 remove @newnode from @peer->allowedips_list before freeing it.
  11
  12 syzbot reported:
  13
  14 BUG: KASAN: use-after-free in __list_del_entry_valid+0xdc/0xf5 lib/list_debug.c:54
  15 Read of size 8 at addr ffff88809881a538 by task syz-executor.4/30133
  16
  17 CPU: 0 PID: 30133 Comm: syz-executor.4 Not tainted 5.5.0-syzkaller #0
  18 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  19 Call Trace:
  20  __dump_stack lib/dump_stack.c:77 [inline]
  21  dump_stack+0x197/0x210 lib/dump_stack.c:118
  22  print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
  23  __kasan_report.cold+0x1b/0x32 mm/kasan/report.c:506
  24  kasan_report+0x12/0x20 mm/kasan/common.c:639
  25  __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135
  26  __list_del_entry_valid+0xdc/0xf5 lib/list_debug.c:54
  27  __list_del_entry include/linux/list.h:132 [inline]
  28  list_del include/linux/list.h:146 [inline]
  29  root_remove_peer_lists+0x24f/0x4b0 drivers/net/wireguard/allowedips.c:65
  30  wg_allowedips_free+0x232/0x390 drivers/net/wireguard/allowedips.c:300
  31  wg_peer_remove_all+0xd5/0x620 drivers/net/wireguard/peer.c:187
  32  wg_set_device+0xd01/0x1350 drivers/net/wireguard/netlink.c:542
  33  genl_family_rcv_msg_doit net/netlink/genetlink.c:672 [inline]
  34  genl_family_rcv_msg net/netlink/genetlink.c:717 [inline]
  35  genl_rcv_msg+0x67d/0xea0 net/netlink/genetlink.c:734
  36  netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
  37  genl_rcv+0x29/0x40 net/netlink/genetlink.c:745
  38  netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
  39  netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328
  40  netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
  41  sock_sendmsg_nosec net/socket.c:652 [inline]
  42  sock_sendmsg+0xd7/0x130 net/socket.c:672
  43  ____sys_sendmsg+0x753/0x880 net/socket.c:2343
  44  ___sys_sendmsg+0x100/0x170 net/socket.c:2397
  45  __sys_sendmsg+0x105/0x1d0 net/socket.c:2430
  46  __do_sys_sendmsg net/socket.c:2439 [inline]
  47  __se_sys_sendmsg net/socket.c:2437 [inline]
  48  __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437
  49  do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
  50  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  51 RIP: 0033:0x45b399
  52 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
  53 RSP: 002b:00007f99a9bcdc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
  54 RAX: ffffffffffffffda RBX: 00007f99a9bce6d4 RCX: 000000000045b399
  55 RDX: 0000000000000000 RSI: 0000000020001340 RDI: 0000000000000003
  56 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
  57 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
  58 R13: 00000000000009ba R14: 00000000004cb2b8 R15: 0000000000000009
  59
  60 Allocated by task 30103:
  61  save_stack+0x23/0x90 mm/kasan/common.c:72
  62  set_track mm/kasan/common.c:80 [inline]
  63  __kasan_kmalloc mm/kasan/common.c:513 [inline]
  64  __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486
  65  kasan_kmalloc+0x9/0x10 mm/kasan/common.c:527
  66  kmem_cache_alloc_trace+0x158/0x790 mm/slab.c:3551
  67  kmalloc include/linux/slab.h:556 [inline]
  68  kzalloc include/linux/slab.h:670 [inline]
  69  add+0x70a/0x1970 drivers/net/wireguard/allowedips.c:236
  70  wg_allowedips_insert_v4+0xf6/0x160 drivers/net/wireguard/allowedips.c:320
  71  set_allowedip drivers/net/wireguard/netlink.c:343 [inline]
  72  set_peer+0xfb9/0x1150 drivers/net/wireguard/netlink.c:468
  73  wg_set_device+0xbd4/0x1350 drivers/net/wireguard/netlink.c:591
  74  genl_family_rcv_msg_doit net/netlink/genetlink.c:672 [inline]
  75  genl_family_rcv_msg net/netlink/genetlink.c:717 [inline]
  76  genl_rcv_msg+0x67d/0xea0 net/netlink/genetlink.c:734
  77  netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
  78  genl_rcv+0x29/0x40 net/netlink/genetlink.c:745
  79  netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
  80  netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328
  81  netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
  82  sock_sendmsg_nosec net/socket.c:652 [inline]
  83  sock_sendmsg+0xd7/0x130 net/socket.c:672
  84  ____sys_sendmsg+0x753/0x880 net/socket.c:2343
  85  ___sys_sendmsg+0x100/0x170 net/socket.c:2397
  86  __sys_sendmsg+0x105/0x1d0 net/socket.c:2430
  87  __do_sys_sendmsg net/socket.c:2439 [inline]
  88  __se_sys_sendmsg net/socket.c:2437 [inline]
  89  __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437
  90  do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
  91  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  92
  93 Freed by task 30103:
  94  save_stack+0x23/0x90 mm/kasan/common.c:72
  95  set_track mm/kasan/common.c:80 [inline]
  96  kasan_set_free_info mm/kasan/common.c:335 [inline]
  97  __kasan_slab_free+0x102/0x150 mm/kasan/common.c:474
  98  kasan_slab_free+0xe/0x10 mm/kasan/common.c:483
  99  __cache_free mm/slab.c:3426 [inline]
 100  kfree+0x10a/0x2c0 mm/slab.c:3757
 101  add+0x12d2/0x1970 drivers/net/wireguard/allowedips.c:266
 102  wg_allowedips_insert_v4+0xf6/0x160 drivers/net/wireguard/allowedips.c:320
 103  set_allowedip drivers/net/wireguard/netlink.c:343 [inline]
 104  set_peer+0xfb9/0x1150 drivers/net/wireguard/netlink.c:468
 105  wg_set_device+0xbd4/0x1350 drivers/net/wireguard/netlink.c:591
 106  genl_family_rcv_msg_doit net/netlink/genetlink.c:672 [inline]
 107  genl_family_rcv_msg net/netlink/genetlink.c:717 [inline]
 108  genl_rcv_msg+0x67d/0xea0 net/netlink/genetlink.c:734
 109  netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
 110  genl_rcv+0x29/0x40 net/netlink/genetlink.c:745
 111  netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 112  netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328
 113  netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
 114  sock_sendmsg_nosec net/socket.c:652 [inline]
 115  sock_sendmsg+0xd7/0x130 net/socket.c:672
 116  ____sys_sendmsg+0x753/0x880 net/socket.c:2343
 117  ___sys_sendmsg+0x100/0x170 net/socket.c:2397
 118  __sys_sendmsg+0x105/0x1d0 net/socket.c:2430
 119  __do_sys_sendmsg net/socket.c:2439 [inline]
 120  __se_sys_sendmsg net/socket.c:2437 [inline]
 121  __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437
 122  do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 123  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 124
 125 The buggy address belongs to the object at ffff88809881a500
 126  which belongs to the cache kmalloc-64 of size 64
 127 The buggy address is located 56 bytes inside of
 128  64-byte region [ffff88809881a500, ffff88809881a540)
 129 The buggy address belongs to the page:
 130 page:ffffea0002620680 refcount:1 mapcount:0 mapping:ffff8880aa400380 index:0x0
 131 raw: 00fffe0000000200 ffffea000250b748 ffffea000254bac8 ffff8880aa400380
 132 raw: 0000000000000000 ffff88809881a000 0000000100000020 0000000000000000
 133 page dumped because: kasan: bad access detected
 134
 135 Memory state around the buggy address:
 136  ffff88809881a400: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 137  ffff88809881a480: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
 138 >ffff88809881a500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 139                                         ^
 140  ffff88809881a580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 141  ffff88809881a600: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
 142
 143 Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
 144 Signed-off-by: Eric Dumazet <edumazet@google.com>
 145 Reported-by: syzbot <syzkaller@googlegroups.com>
 146 Cc: Jason A. Donenfeld <Jason@zx2c4.com>
 147 Cc: wireguard@lists.zx2c4.com
 148 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
 149 Signed-off-by: David S. Miller <davem@davemloft.net>
 150 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
 151 ---
 152  drivers/net/wireguard/allowedips.c | 1 +
 153  1 file changed, 1 insertion(+)
 154
 155 --- a/drivers/net/wireguard/allowedips.c
 156 +++ b/drivers/net/wireguard/allowedips.c
 157 @@ -263,6 +263,7 @@ static int add(struct allowedips_node __
 158         } else {
 159                 node = kzalloc(sizeof(*node), GFP_KERNEL);
 160                 if (unlikely(!node)) {
 161 +                       list_del(&newnode->peer_list);
 162                         kfree(newnode);
 163                         return -ENOMEM;
 164                 }