queue-4.19/nfc-ensure-presence-of-required-attributes-in-the-deactivate_target-handler.patch

   1 From foo@baz Wed 19 Jun 2019 02:34:37 PM CEST
   2 From: Young Xiao <92siuyang@gmail.com>
   3 Date: Fri, 14 Jun 2019 15:13:02 +0800
   4 Subject: nfc: Ensure presence of required attributes in the deactivate_target handler
   5
   6 From: Young Xiao <92siuyang@gmail.com>
   7
   8 [ Upstream commit 385097a3675749cbc9e97c085c0e5dfe4269ca51 ]
   9
  10 Check that the NFC_ATTR_TARGET_INDEX attributes (in addition to
  11 NFC_ATTR_DEVICE_INDEX) are provided by the netlink client prior to
  12 accessing them. This prevents potential unhandled NULL pointer dereference
  13 exceptions which can be triggered by malicious user-mode programs,
  14 if they omit one or both of these attributes.
  15
  16 Signed-off-by: Young Xiao <92siuyang@gmail.com>
  17 Signed-off-by: David S. Miller <davem@davemloft.net>
  18 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  19 ---
  20  net/nfc/netlink.c |    3 ++-
  21  1 file changed, 2 insertions(+), 1 deletion(-)
  22
  23 --- a/net/nfc/netlink.c
  24 +++ b/net/nfc/netlink.c
  25 @@ -922,7 +922,8 @@ static int nfc_genl_deactivate_target(st
  26         u32 device_idx, target_idx;
  27         int rc;
  28
  29 -       if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
  30 +       if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
  31 +           !info->attrs[NFC_ATTR_TARGET_INDEX])
  32                 return -EINVAL;
  33
  34         device_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);