[ 046/187] NFC: Prevent multiple buffer overflows in NCI

Greg Kroah-Hartman
2012-07-12T23:40:07Z

From: Dan Rosenberg <dan.j.rosenberg@gmail.com>

commit 67de956ff5dc1d4f321e16cfbd63f5be3b691b43 upstream.

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: 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/nfc/nci/ntf.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

--- a/net/nfc/nci/ntf.c
+++ b/net/nfc/nci/ntf.c
@@ -106,7 +106,7 @@ static __u8 *nci_extract_rf_params_nfca_
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_
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_
__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
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

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,