From: Defang Bo <bodefang@xxxxxxx> [ Upstream commit 280e3ebdafb863b3cb50d5842f056267e15bf40c ] 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. Similar to commit a0323b979f81 ("nfc: Ensure presence of required attributes in the activate_target handler"). Fixes: 9674da8759df ("NFC: Add firmware upload netlink command") Signed-off-by: Defang Bo <bodefang@xxxxxxx> Link: https://lore.kernel.org/r/1603107538-4744-1-git-send-email-bodefang@xxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/nfc/netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/nfc/netlink.c +++ b/net/nfc/netlink.c @@ -1227,7 +1227,7 @@ static int nfc_genl_fw_download(struct s 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]);