NFC: Prevent multiple buffer overflows in NCI

Fix multiple remotely-exploitable stack-based buffer overflows due to
the NCI code pulling length fields directly from incoming frames and
copying too much data into statically-sized arrays.

Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Cc: stable@kernel.org
Cc: security@kernel.org
Cc: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
Cc: Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Acked-by: Ilan Elias <ilane@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/net/nfc/nci/ntf.c b/net/nfc/nci/ntf.c
index cb2646179e5f8b8d1836499579d1ccfd109fad60..2ab196a9f228ac873238c2a060685bacea62b87a 100644 (file)
--- a/net/nfc/nci/ntf.c
+++ b/net/nfc/nci/ntf.c
@@ -106,7 +106,7 @@ static __u8 *nci_extract_rf_params_nfca_passive_poll(struct nci_dev *ndev,
        nfca_poll->sens_res = __le16_to_cpu(*((__u16 *)data));
        data += 2;
 
-       nfca_poll->nfcid1_len = *data++;
+       nfca_poll->nfcid1_len = min_t(__u8, *data++, NFC_NFCID1_MAXSIZE);
 
        pr_debug("sens_res 0x%x, nfcid1_len %d\n",
                 nfca_poll->sens_res, nfca_poll->nfcid1_len);
@@ -130,7 +130,7 @@ static __u8 *nci_extract_rf_params_nfcb_passive_poll(struct nci_dev *ndev,
                        struct rf_tech_specific_params_nfcb_poll *nfcb_poll,
                                                     __u8 *data)
 {
-       nfcb_poll->sensb_res_len = *data++;
+       nfcb_poll->sensb_res_len = min_t(__u8, *data++, NFC_SENSB_RES_MAXSIZE);
 
        pr_debug("sensb_res_len %d\n", nfcb_poll->sensb_res_len);
 
@@ -145,7 +145,7 @@ static __u8 *nci_extract_rf_params_nfcf_passive_poll(struct nci_dev *ndev,
                                                     __u8 *data)
 {
        nfcf_poll->bit_rate = *data++;
-       nfcf_poll->sensf_res_len = *data++;
+       nfcf_poll->sensf_res_len = min_t(__u8, *data++, NFC_SENSF_RES_MAXSIZE);
 
        pr_debug("bit_rate %d, sensf_res_len %d\n",
                 nfcf_poll->bit_rate, nfcf_poll->sensf_res_len);
@@ -331,7 +331,7 @@ static int nci_extract_activation_params_iso_dep(struct nci_dev *ndev,
        switch (ntf->activation_rf_tech_and_mode) {
        case NCI_NFC_A_PASSIVE_POLL_MODE:
                nfca_poll = &ntf->activation_params.nfca_poll_iso_dep;
-               nfca_poll->rats_res_len = *data++;
+               nfca_poll->rats_res_len = min_t(__u8, *data++, 20);
                pr_debug("rats_res_len %d\n", nfca_poll->rats_res_len);
                if (nfca_poll->rats_res_len > 0) {
                        memcpy(nfca_poll->rats_res,
@@ -341,7 +341,7 @@ static int nci_extract_activation_params_iso_dep(struct nci_dev *ndev,
 
        case NCI_NFC_B_PASSIVE_POLL_MODE:
                nfcb_poll = &ntf->activation_params.nfcb_poll_iso_dep;
-               nfcb_poll->attrib_res_len = *data++;
+               nfcb_poll->attrib_res_len = min_t(__u8, *data++, 50);
                pr_debug("attrib_res_len %d\n", nfcb_poll->attrib_res_len);
                if (nfcb_poll->attrib_res_len > 0) {
                        memcpy(nfcb_poll->attrib_res,