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

   1 From 80ced5ac18af3ef4dc9300fd6b152a732891cdb1 Mon Sep 17 00:00:00 2001
   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
   5  handler
   6
   7 [ Upstream commit 385097a3675749cbc9e97c085c0e5dfe4269ca51 ]
   8
   9 Check that the NFC_ATTR_TARGET_INDEX attributes (in addition to
  10 NFC_ATTR_DEVICE_INDEX) are provided by the netlink client prior to
  11 accessing them. This prevents potential unhandled NULL pointer dereference
  12 exceptions which can be triggered by malicious user-mode programs,
  13 if they omit one or both of these attributes.
  14
  15 Signed-off-by: Young Xiao <92siuyang@gmail.com>
  16 Signed-off-by: David S. Miller <davem@davemloft.net>
  17 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  18 ---
  19  net/nfc/netlink.c | 3 ++-
  20  1 file changed, 2 insertions(+), 1 deletion(-)
  21
  22 diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
  23 index 376181cc1def..9f2875efb4ac 100644
  24 --- a/net/nfc/netlink.c
  25 +++ b/net/nfc/netlink.c
  26 @@ -922,7 +922,8 @@ static int nfc_genl_deactivate_target(struct sk_buff *skb,
  27         u32 device_idx, target_idx;
  28         int rc;
  29
  30 -       if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
  31 +       if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
  32 +           !info->attrs[NFC_ATTR_TARGET_INDEX])
  33                 return -EINVAL;
  34
  35         device_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
  36 --
  37 2.20.1
  38