queue-5.10/mac802154-fix-llsec-key-resources-release-in-mac8021.patch

   1 From 04a80b4287a734d61e96b8255fc3663fd4f3e14b Mon Sep 17 00:00:00 2001
   2 From: Sasha Levin <sashal@kernel.org>
   3 Date: Wed, 28 Feb 2024 19:38:39 +0300
   4 Subject: mac802154: fix llsec key resources release in mac802154_llsec_key_del
   5
   6 From: Fedor Pchelkin <pchelkin@ispras.ru>
   7
   8 [ Upstream commit e8a1e58345cf40b7b272e08ac7b32328b2543e40 ]
   9
  10 mac802154_llsec_key_del() can free resources of a key directly without
  11 following the RCU rules for waiting before the end of a grace period. This
  12 may lead to use-after-free in case llsec_lookup_key() is traversing the
  13 list of keys in parallel with a key deletion:
  14
  15 refcount_t: addition on 0; use-after-free.
  16 WARNING: CPU: 4 PID: 16000 at lib/refcount.c:25 refcount_warn_saturate+0x162/0x2a0
  17 Modules linked in:
  18 CPU: 4 PID: 16000 Comm: wpan-ping Not tainted 6.7.0 #19
  19 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
  20 RIP: 0010:refcount_warn_saturate+0x162/0x2a0
  21 Call Trace:
  22  <TASK>
  23  llsec_lookup_key.isra.0+0x890/0x9e0
  24  mac802154_llsec_encrypt+0x30c/0x9c0
  25  ieee802154_subif_start_xmit+0x24/0x1e0
  26  dev_hard_start_xmit+0x13e/0x690
  27  sch_direct_xmit+0x2ae/0xbc0
  28  __dev_queue_xmit+0x11dd/0x3c20
  29  dgram_sendmsg+0x90b/0xd60
  30  __sys_sendto+0x466/0x4c0
  31  __x64_sys_sendto+0xe0/0x1c0
  32  do_syscall_64+0x45/0xf0
  33  entry_SYSCALL_64_after_hwframe+0x6e/0x76
  34
  35 Also, ieee802154_llsec_key_entry structures are not freed by
  36 mac802154_llsec_key_del():
  37
  38 unreferenced object 0xffff8880613b6980 (size 64):
  39   comm "iwpan", pid 2176, jiffies 4294761134 (age 60.475s)
  40   hex dump (first 32 bytes):
  41     78 0d 8f 18 80 88 ff ff 22 01 00 00 00 00 ad de  x.......".......
  42     00 00 00 00 00 00 00 00 03 00 cd ab 00 00 00 00  ................
  43   backtrace:
  44     [<ffffffff81dcfa62>] __kmem_cache_alloc_node+0x1e2/0x2d0
  45     [<ffffffff81c43865>] kmalloc_trace+0x25/0xc0
  46     [<ffffffff88968b09>] mac802154_llsec_key_add+0xac9/0xcf0
  47     [<ffffffff8896e41a>] ieee802154_add_llsec_key+0x5a/0x80
  48     [<ffffffff8892adc6>] nl802154_add_llsec_key+0x426/0x5b0
  49     [<ffffffff86ff293e>] genl_family_rcv_msg_doit+0x1fe/0x2f0
  50     [<ffffffff86ff46d1>] genl_rcv_msg+0x531/0x7d0
  51     [<ffffffff86fee7a9>] netlink_rcv_skb+0x169/0x440
  52     [<ffffffff86ff1d88>] genl_rcv+0x28/0x40
  53     [<ffffffff86fec15c>] netlink_unicast+0x53c/0x820
  54     [<ffffffff86fecd8b>] netlink_sendmsg+0x93b/0xe60
  55     [<ffffffff86b91b35>] ____sys_sendmsg+0xac5/0xca0
  56     [<ffffffff86b9c3dd>] ___sys_sendmsg+0x11d/0x1c0
  57     [<ffffffff86b9c65a>] __sys_sendmsg+0xfa/0x1d0
  58     [<ffffffff88eadbf5>] do_syscall_64+0x45/0xf0
  59     [<ffffffff890000ea>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
  60
  61 Handle the proper resource release in the RCU callback function
  62 mac802154_llsec_key_del_rcu().
  63
  64 Note that if llsec_lookup_key() finds a key, it gets a refcount via
  65 llsec_key_get() and locally copies key id from key_entry (which is a
  66 list element). So it's safe to call llsec_key_put() and free the list
  67 entry after the RCU grace period elapses.
  68
  69 Found by Linux Verification Center (linuxtesting.org).
  70
  71 Fixes: 5d637d5aabd8 ("mac802154: add llsec structures and mutators")
  72 Cc: stable@vger.kernel.org
  73 Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
  74 Acked-by: Alexander Aring <aahringo@redhat.com>
  75 Message-ID: <20240228163840.6667-1-pchelkin@ispras.ru>
  76 Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
  77 Signed-off-by: Sasha Levin <sashal@kernel.org>
  78 ---
  79  include/net/cfg802154.h |  1 +
  80  net/mac802154/llsec.c   | 18 +++++++++++++-----
  81  2 files changed, 14 insertions(+), 5 deletions(-)
  82
  83 diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
  84 index 6ed07844eb244..5290781abba3d 100644
  85 --- a/include/net/cfg802154.h
  86 +++ b/include/net/cfg802154.h
  87 @@ -257,6 +257,7 @@ struct ieee802154_llsec_key {
  88
  89  struct ieee802154_llsec_key_entry {
  90         struct list_head list;
  91 +       struct rcu_head rcu;
  92
  93         struct ieee802154_llsec_key_id id;
  94         struct ieee802154_llsec_key *key;
  95 diff --git a/net/mac802154/llsec.c b/net/mac802154/llsec.c
  96 index 55550ead2ced8..a4cc9d077c59c 100644
  97 --- a/net/mac802154/llsec.c
  98 +++ b/net/mac802154/llsec.c
  99 @@ -265,19 +265,27 @@ int mac802154_llsec_key_add(struct mac802154_llsec *sec,
 100         return -ENOMEM;
 101  }
 102
 103 +static void mac802154_llsec_key_del_rcu(struct rcu_head *rcu)
 104 +{
 105 +       struct ieee802154_llsec_key_entry *pos;
 106 +       struct mac802154_llsec_key *mkey;
 107 +
 108 +       pos = container_of(rcu, struct ieee802154_llsec_key_entry, rcu);
 109 +       mkey = container_of(pos->key, struct mac802154_llsec_key, key);
 110 +
 111 +       llsec_key_put(mkey);
 112 +       kfree_sensitive(pos);
 113 +}
 114 +
 115  int mac802154_llsec_key_del(struct mac802154_llsec *sec,
 116                             const struct ieee802154_llsec_key_id *key)
 117  {
 118         struct ieee802154_llsec_key_entry *pos;
 119
 120         list_for_each_entry(pos, &sec->table.keys, list) {
 121 -               struct mac802154_llsec_key *mkey;
 122 -
 123 -               mkey = container_of(pos->key, struct mac802154_llsec_key, key);
 124 -
 125                 if (llsec_key_id_equal(&pos->id, key)) {
 126                         list_del_rcu(&pos->list);
 127 -                       llsec_key_put(mkey);
 128 +                       call_rcu(&pos->rcu, mac802154_llsec_key_del_rcu);
 129                         return 0;
 130                 }
 131         }
 132 --
 133 2.43.0
 134