diff options
| author | Kees Cook <keescook@chromium.org> | 2018-02-14 15:45:07 -0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-06-16 22:22:18 +0100 |
| commit | 3b3a343e2442a4fb2730967df4e2a29f0fa66c84 (patch) | |
| tree | dd4172b9ef38b702f87186bcc0dde74bab813d69 | |
| parent | fa25a8b46e7f4abba6c7acab95c7791b841a9c48 (diff) | |
| download | linux-stable-3b3a343e2442a4fb2730967df4e2a29f0fa66c84.tar.gz linux-stable-3b3a343e2442a4fb2730967df4e2a29f0fa66c84.tar.bz2 linux-stable-3b3a343e2442a4fb2730967df4e2a29f0fa66c84.zip | |
NFC: llcp: Limit size of SDP URI
commit fe9c842695e26d8116b61b80bfb905356f07834b upstream.
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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -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 a3ad69a4c648..1e7245792fc0 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 43cb1c17e267..d44369ed1436 100644 --- a/net/nfc/netlink.c +++ b/net/nfc/netlink.c @@ -60,7 +60,8 @@ 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 }, }; |