[PATCH 4.18 082/135] Bluetooth: SMP: Fix trying to use non-existent local OOB data

Greg Kroah-Hartman
2018-10-16T17:15:26Z

From: Johan Hedberg <johan.hedberg@intel.com>

[ Upstream commit 94f14e4728125f979629b2b020d31cd718191626 ]

A remote device may claim that it has received our OOB data, even
though we never geneated it. Add a new flag to track whether we
actually have OOB data, and ignore the remote peer's flag if haven't
generated OOB data.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/bluetooth/smp.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -83,6 +83,7 @@ enum {

struct smp_dev {
/* Secure Connections OOB data */
+ bool local_oob;
u8 local_pk[64];
u8 local_rand[16];
bool debug_key;
@@ -599,6 +600,8 @@ int smp_generate_oob(struct hci_dev *hde

memcpy(rand, smp->local_rand, 16);

+ smp->local_oob = true;
+
return 0;
}

@@ -1785,7 +1788,7 @@ static u8 smp_cmd_pairing_req(struct l2c
* successfully received our local OOB data - therefore set the
* flag to indicate that local OOB is in use.
*/
- if (req->oob_flag == SMP_OOB_PRESENT)
+ if (req->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob)
set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);

/* SMP over BR/EDR requires special treatment */
@@ -1967,7 +1970,7 @@ static u8 smp_cmd_pairing_rsp(struct l2c
* successfully received our local OOB data - therefore set the
* flag to indicate that local OOB is in use.
*/
- if (rsp->oob_flag == SMP_OOB_PRESENT)
+ if (rsp->oob_flag == SMP_OOB_PRESENT && SMP_DEV(hdev)->local_oob)
set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);

smp->prsp[0] = SMP_CMD_PAIRING_RSP;
@@ -3230,6 +3233,7 @@ static struct l2cap_chan *smp_add_cid(st
return ERR_CAST(tfm_ecdh);
}

+ smp->local_oob = false;
smp->tfm_aes = tfm_aes;
smp->tfm_cmac = tfm_cmac;
smp->tfm_ecdh = tfm_ecdh;