[PATCH] nfc: Ensure presence of NFC_ATTR_FIRMWARE_NAME attribute in nfc_genl_fw_download()

From: Defang Bo
Date: Mon Oct 19 2020 - 08:11:10 EST


check that the NFC_ATTR_FIRMWARE_NAME attributes 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. Just similar to commit <a0323b979f81>("nfc: Ensure presence of required attributes in the activate_target handler").

Signed-off-by: Defang Bo <bodefang@xxxxxxx>
---
net/nfc/netlink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index e894254..8709f3d 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -1217,7 +1217,7 @@ static int nfc_genl_fw_download(struct sk_buff *skb, struct genl_info *info)
u32 idx;
char firmware_name[NFC_FIRMWARE_NAME_MAXSIZE + 1];

- if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
+ if (!info->attrs[NFC_ATTR_DEVICE_INDEX] || !info->attrs[NFC_ATTR_FIRMWARE_NAME])
return -EINVAL;

idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
--
1.9.1