In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: refuse __l2cap_chan_add if chan already has conn l2cap_chan may be linked to l2cap_conn at most once. This is assumed in several places, eg l2cap_chan_del cleanup. There is a TOCTOU race where the invariant is violated: [Task 1] [Task 2] l2cap_chan_connect l2cap_sock_bind l2cap_chan_lock lock_sock l2cap_state_change if (sk->sk_state != BT_OPEN) chan->state = BT_CONNECT l2cap_sock_state_change_cb chan->state = BT_BOUND sk->sk_state = BT_BOUND lock_sock <------------------ release_sock sk->sk_state = BT_CONNECT l2cap_sock_connect() does not check sk->sk_state, so since chan->state is now BT_BOUND, subsequent connect() ends up with second __l2cap_chan_add. Explicitly document and check the invariant in __l2cap_chan_add with WARN_ON_ONCE. The only callsite where it could be hit is l2cap_chan_connect, so add pre-check there to avoid relying on chan->state. chan->state read/write is not properly guarded currently so there can be other TOCTOUC problems. Add l2cap_lock_chan in l2cap_sock_bind() to guard chan->state write.
Daten: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Wiedergegeben wie in der Quelle, auf Englisch.
| Hersteller | Produkt | Versionen | |
|---|---|---|---|
| Linux | Linux | 5.10.265 – < 5.10.273, 5.15.216 – < 5.15.224, 6.1.183 – < 6.1.191, 6.6.145 – < 6.6.161, 6.12.97 – < 6.12.115, 6.18.39 – < 6.18.60, 7.1.4 – < 7.2 | |
| linux | linux kernel | 5.10.265 – < 5.10.273 |
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