From d1ac8a98f312da20784723b53c62ad67766d5cb7 Mon Sep 17 00:00:00 2001 From: Mateusz Jurczyk Date: Wed, 24 May 2017 12:42:26 +0200 Subject: nfc: Ensure presence of required attributes in the activate_target handler commit a0323b979f81ad2deb2c8836eab506534891876a upstream. Check that the NFC_ATTR_TARGET_INDEX and NFC_ATTR_PROTOCOLS 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: Mateusz Jurczyk Acked-by: Kees Cook Signed-off-by: Samuel Ortiz Signed-off-by: Greg Kroah-Hartman --- net/nfc/netlink.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c index ea023b35f1c2..102c681c48b5 100644 --- a/net/nfc/netlink.c +++ b/net/nfc/netlink.c @@ -910,7 +910,9 @@ static int nfc_genl_activate_target(struct sk_buff *skb, struct genl_info *info) u32 device_idx, target_idx, protocol; int rc; - if (!info->attrs[NFC_ATTR_DEVICE_INDEX]) + if (!info->attrs[NFC_ATTR_DEVICE_INDEX] || + !info->attrs[NFC_ATTR_TARGET_INDEX] || + !info->attrs[NFC_ATTR_PROTOCOLS]) return -EINVAL; device_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]); -- cgit v1.2.3