NFC: llcp: Limit size of SDP URI
The tlv_len is u8, so we need to limit the size of the SDP URI. Enforce
this both in the NLA policy and in the code that performs the allocation
and copy, to avoid writing past the end of the allocated buffer.
Fixes: d9b8d8e19b073 ("NFC: llcp: Service Name Lookup netlink interface")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index c0b83dc..f018eaf 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -61,7 +61,8 @@ static const struct nla_policy nfc_genl_policy[NFC_ATTR_MAX + 1] = {
};
static const struct nla_policy nfc_sdp_genl_policy[NFC_SDP_ATTR_MAX + 1] = {
- [NFC_SDP_ATTR_URI] = { .type = NLA_STRING },
+ [NFC_SDP_ATTR_URI] = { .type = NLA_STRING,
+ .len = U8_MAX - 4 },
[NFC_SDP_ATTR_SAP] = { .type = NLA_U8 },
};