Since u32 range size is not a multiple of 1,000,000, current passkey generation 
logic is biased.

Fixed this by adding a routine that selects passkey again if passkey is 
4,200,000,000 or more.

Signed-off-by: Mincheol Son <encrypted....@gmail.com>
---
 net/bluetooth/smp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index c659c464f7ca..26ed83e0db34 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -922,7 +922,9 @@ static int tk_request(struct l2cap_conn *conn, u8 
remote_oob, u8 auth,
        /* Generate random passkey. */
        if (smp->method == CFM_PASSKEY) {
                memset(smp->tk, 0, sizeof(smp->tk));
-               get_random_bytes(&passkey, sizeof(passkey));
+               do {
+                       get_random_bytes(&passkey, sizeof(passkey));
+               } while (passkey >= (u32)4200000000);
                passkey %= 1000000;
                put_unaligned_le32(passkey, smp->tk);
                BT_DBG("PassKey: %d", passkey);
-- 
2.25.1

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