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| author | Luiz Augusto von Dentz <luiz.von.dentz@intel.com> | 2023-10-05 13:59:59 -0700 |
|---|---|---|
| committer | Luiz Augusto von Dentz <luiz.von.dentz@intel.com> | 2023-10-13 20:00:25 -0700 |
| commit | b541260615f601ae1b5d6d0cc54e790de706303b (patch) | |
| tree | 9d92fd16e9079d287f166de53e96023cc9f7f499 | |
| parent | c7f59461f5a78994613afc112cdd73688aef9076 (diff) | |
| download | linux-b541260615f601ae1b5d6d0cc54e790de706303b.tar.gz linux-b541260615f601ae1b5d6d0cc54e790de706303b.tar.bz2 linux-b541260615f601ae1b5d6d0cc54e790de706303b.zip | |
Bluetooth: hci_event: Fix using memcmp when comparing keys
memcmp is not consider safe to use with cryptographic secrets:
'Do not use memcmp() to compare security critical data, such as
cryptographic secrets, because the required CPU time depends on the
number of equal bytes.'
While usage of memcmp for ZERO_KEY may not be considered a security
critical data, it can lead to more usage of memcmp with pairing keys
which could introduce more security problems.
Fixes: 455c2ff0a558 ("Bluetooth: Fix BR/EDR out-of-band pairing with only initiator data")
Fixes: 33155c4aae52 ("Bluetooth: hci_event: Ignore NULL link key")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
| -rw-r--r-- | net/bluetooth/hci_event.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 7e1c875e0e88..9b252a65a7cd 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -26,6 +26,8 @@ /* Bluetooth HCI event handling. */ #include <asm/unaligned.h> +#include <linux/crypto.h> +#include <crypto/algapi.h> #include <net/bluetooth/bluetooth.h> #include <net/bluetooth/hci_core.h> @@ -4754,7 +4756,7 @@ static void hci_link_key_notify_evt(struct hci_dev *hdev, void *data, goto unlock; /* Ignore NULL link key against CVE-2020-26555 */ - if (!memcmp(ev->link_key, ZERO_KEY, HCI_LINK_KEY_SIZE)) { + if (!crypto_memneq(ev->link_key, ZERO_KEY, HCI_LINK_KEY_SIZE)) { bt_dev_dbg(hdev, "Ignore NULL link key (ZERO KEY) for %pMR", &ev->bdaddr); hci_disconnect(conn, HCI_ERROR_AUTH_FAILURE); @@ -5294,8 +5296,8 @@ static u8 bredr_oob_data_present(struct hci_conn *conn) * available, then do not declare that OOB data is * present. */ - if (!memcmp(data->rand256, ZERO_KEY, 16) || - !memcmp(data->hash256, ZERO_KEY, 16)) + if (!crypto_memneq(data->rand256, ZERO_KEY, 16) || + !crypto_memneq(data->hash256, ZERO_KEY, 16)) return 0x00; return 0x02; @@ -5305,8 +5307,8 @@ static u8 bredr_oob_data_present(struct hci_conn *conn) * not supported by the hardware, then check that if * P-192 data values are present. */ - if (!memcmp(data->rand192, ZERO_KEY, 16) || - !memcmp(data->hash192, ZERO_KEY, 16)) + if (!crypto_memneq(data->rand192, ZERO_KEY, 16) || + !crypto_memneq(data->hash192, ZERO_KEY, 16)) return 0x00; return 0x01; |