CVE-2026-80683
CVE-2026-80683 is a security vulnerability. O3 Security confirms whether CVE-2026-80683 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: SCO: give the socket its own sco_conn reference sco_conn_del() drops a reference it does not own. It…
Description
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: SCO: give the socket its own sco_conn reference
sco_conn_del() drops a reference it does not own. It takes one transient reference via sco_conn_hold_unless_zero() and releases it with the sco_conn_put() that follows sco_sock_hold(); the additional put in the !sk branch releases a second one:
conn = sco_conn_hold_unless_zero(conn);
...
sk = sco_sock_hold(conn);
sco_conn_unlock(conn);
sco_conn_put(conn);
if (!sk) {
sco_conn_put(conn);
return;
}
When close() races the controller's Disconnection Complete, sco_chan_del() clears conn->sk and drops the socket's reference while sco_conn_del() is running. sco_conn_del() then sees sk == NULL, its own put drops the count to zero and frees the conn, and the second put writes to the freed kref:
BUG: KASAN: slab-use-after-free in sco_conn_put.part.0+0x1a/0x190
Write of size 4 at addr ffff8881099dec74 by task kworker/u17:3/413
Workqueue: hci1 hci_rx_work
Call Trace:
sco_conn_put.part.0+0x1a/0x190
hci_disconn_complete_evt+0x1ee/0x3e0
hci_event_packet+0x54a/0x650
hci_rx_work+0x321/0x3d0
Allocated by task 413:
sco_conn_add+0x72/0x1a0
sco_connect_cfm+0x88/0x670
Freed by task 413:
sco_conn_del.isra.0+0x3f/0xf0
hci_disconn_complete_evt+0x1ee/0x3e0
refcount_t: underflow; use-after-free.
The root cause is that the socket stores the connection without holding a reference of its own. __sco_chan_add() does:
sco_pi(sk)->conn = conn;
so the socket borrows whatever reference its caller happened to hold, and the callers paper over that with ad-hoc holds and puts. Give the socket a counted reference instead: __sco_chan_add() takes one and it is released together with the channel (sco_chan_del()) and in sco_sock_destruct(). With the socket holding its own reference, sco_conn_del() no longer needs the extra put and the redundant hold in sco_conn_ready() goes away.
Making the socket own its reference means the connection is now actually freed on the error paths of sco_connect() where it used to leak, which in turn runs sco_conn_free() and its hci_conn_drop(conn->hcon). To keep the hci_conn accounting balanced, make that ownership explicit as well: sco_conn_add() consumes one hci_conn reference and the sco_conn owns it for its lifetime. sco_connect() hands over the reference returned by hci_connect_sco() and no longer drops it on the error paths; sco_connect_cfm(), which is not given a reference, takes one with hci_conn_hold() before handing it to sco_conn_add() (and drops it again if the allocation fails); and the explicit hci_conn_hold() in sco_conn_ready() is removed. Every reference then has a single, clear owner.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-80683 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-80683 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-80683. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-80683 in your dependencies?
O3 detects CVE-2026-80683 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.