From 385097a3675749cbc9e97c085c0e5dfe4269ca51 Mon Sep 17 00:00:00 2001 From: Young Xiao <92siuyang@gmail.com> Date: Fri, 14 Jun 2019 15:13:02 +0800 Subject: [PATCH] nfc: Ensure presence of required attributes in the deactivate_target handler Check that the NFC_ATTR_TARGET_INDEX attributes (in addition to NFC_ATTR_DEVICE_INDEX) are provided by the netlink client prior to accessing them. This prevents potential unhandled NULL pointer dereference exceptions which can be triggered by malicious user-mode programs, if they omit one or both of these attributes. Signed-off-by: Young Xiao <92siuyang@gmail.com> Signed-off-by: David S. Miller --- net/nfc/netlink.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c index 1180b3e58a0a..ea64c90b14e8 100644 --- a/net/nfc/netlink.c +++ b/net/nfc/netlink.c @@ -911,7 +911,8 @@ static int nfc_genl_deactivate_target(struct sk_buff *skb, u32 device_idx, target_idx; int rc; - if (!info->attrs[NFC_ATTR_DEVICE_INDEX]) + if (!info->attrs[NFC_ATTR_DEVICE_INDEX] || + !info->attrs[NFC_ATTR_TARGET_INDEX]) return -EINVAL; device_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]); -- 2.39.5