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| author | Kees Cook <keescook@chromium.org> | 2018-02-14 15:45:07 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-02-16 15:16:05 -0500 |
| commit | fe9c842695e26d8116b61b80bfb905356f07834b (patch) | |
| tree | 4290060a267efbab9953477c6e8a0e5751be97e2 | |
| parent | c410c1966fe6fcfb23bcac0924aaa6a6e7449829 (diff) | |
| download | linux-0-day-fe9c842695e26d8116b61b80bfb905356f07834b.tar.gz linux-0-day-fe9c842695e26d8116b61b80bfb905356f07834b.tar.xz | |
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>
| -rw-r--r-- | net/nfc/llcp_commands.c | 4 | ||||
| -rw-r--r-- | net/nfc/netlink.c | 3 |
2 files changed, 6 insertions, 1 deletions
diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c index 367d8c0271018..2ceefa183ceed 100644 --- a/net/nfc/llcp_commands.c +++ b/net/nfc/llcp_commands.c @@ -149,6 +149,10 @@ struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, char *uri, pr_debug("uri: %s, len: %zu\n", uri, uri_len); + /* sdreq->tlv_len is u8, takes uri_len, + 3 for header, + 1 for NULL */ + if (WARN_ON_ONCE(uri_len > U8_MAX - 4)) + return NULL; + sdreq = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL); if (sdreq == NULL) return NULL; diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c index c0b83dc9d9930..f018eafc2a0de 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 }, }; |