From: Oleh Konko <security@1seal.org> stable inclusion from stable-v5.10.253 commit 9a38659a3d06080715691bd3139f9c4b61f688e3 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14523 CVE: CVE-2026-31773 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ---------------------------------------------------------------------- commit 20756fec2f0108cb88e815941f1ffff88dc286fe upstream. The legacy responder path in smp_random() currently labels the stored STK as authenticated whenever pending_sec_level is BT_SECURITY_HIGH. That reflects what the local service requested, not what the pairing flow actually achieved. For Just Works/Confirm legacy pairing, SMP_FLAG_MITM_AUTH stays clear and the resulting STK should remain unauthenticated even if the local side requested HIGH security. Use the established MITM state when storing the responder STK so the key metadata matches the pairing result. This also keeps the legacy path aligned with the Secure Connections code, which already treats JUST_WORKS/JUST_CFM as unauthenticated. Fixes: fff3490f4781 ("Bluetooth: Fix setting correct authentication information for SMP STK") Cc: stable@vger.kernel.org Signed-off-by: Oleh Konko <security@1seal.org> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chen Jinghuang <chenjinghuang2@huawei.com> --- net/bluetooth/smp.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index d9a378d12be6..d3bc89bbbeb9 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -1017,10 +1017,7 @@ static u8 smp_random(struct smp_chan *smp) smp_s1(smp->tk, smp->prnd, smp->rrnd, stk); - if (hcon->pending_sec_level == BT_SECURITY_HIGH) - auth = 1; - else - auth = 0; + auth = test_bit(SMP_FLAG_MITM_AUTH, &smp->flags) ? 1 : 0; /* Even though there's no _RESPONDER suffix this is the * responder STK we're adding for later lookup (the initiator -- 2.34.1