1. 31 Mar, 2017 2 commits
    • Andy Whitcroft's avatar
      xfrm_user: validate XFRM_MSG_NEWAE XFRMA_REPLAY_ESN_VAL replay_window · cce7e56d
      Andy Whitcroft authored
      commit 677e806d upstream.
      
      When a new xfrm state is created during an XFRM_MSG_NEWSA call we
      validate the user supplied replay_esn to ensure that the size is valid
      and to ensure that the replay_window size is within the allocated
      buffer.  However later it is possible to update this replay_esn via a
      XFRM_MSG_NEWAE call.  There we again validate the size of the supplied
      buffer matches the existing state and if so inject the contents.  We do
      not at this point check that the replay_window is within the allocated
      memory.  This leads to out-of-bounds reads and writes triggered by
      netlink packets.  This leads to memory corruption and the potential for
      priviledge escalation.
      
      We already attempt to validate the incoming replay information in
      xfrm_new_ae() via xfrm_replay_verify_len().  This confirms that the user
      is not trying to change the size of the replay state buffer which
      includes the replay_esn.  It however does not check the replay_window
      remains within that buffer.  Add validation of the contained
      replay_window.
      
      CVE-2017-7184
      Signed-off-by: default avatarAndy Whitcroft <apw@canonical.com>
      Acked-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      cce7e56d
    • Florian Westphal's avatar
      xfrm: policy: init locks early · a9a76a3e
      Florian Westphal authored
      commit c282222a upstream.
      
      Dmitry reports following splat:
       INFO: trying to register non-static key.
       the code is fine but needs lockdep annotation.
       turning off the locking correctness validator.
       CPU: 0 PID: 13059 Comm: syz-executor1 Not tainted 4.10.0-rc7-next-20170207 #1
      [..]
       spin_lock_bh include/linux/spinlock.h:304 [inline]
       xfrm_policy_flush+0x32/0x470 net/xfrm/xfrm_policy.c:963
       xfrm_policy_fini+0xbf/0x560 net/xfrm/xfrm_policy.c:3041
       xfrm_net_init+0x79f/0x9e0 net/xfrm/xfrm_policy.c:3091
       ops_init+0x10a/0x530 net/core/net_namespace.c:115
       setup_net+0x2ed/0x690 net/core/net_namespace.c:291
       copy_net_ns+0x26c/0x530 net/core/net_namespace.c:396
       create_new_namespaces+0x409/0x860 kernel/nsproxy.c:106
       unshare_nsproxy_namespaces+0xae/0x1e0 kernel/nsproxy.c:205
       SYSC_unshare kernel/fork.c:2281 [inline]
      
      Problem is that when we get error during xfrm_net_init we will call
      xfrm_policy_fini which will acquire xfrm_policy_lock before it was
      initialized.  Just move it around so locks get set up first.
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Fixes: 283bc9f3 ("xfrm: Namespacify xfrm state/policy locks")
      Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
      Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a9a76a3e
  2. 30 Mar, 2017 38 commits