0.0
NA
CVE-2026-80683
Bluetooth: SCO: give the socket its own sco_conn reference
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.

INFO

Published Date :

Aug. 28, 2026, 8:16 a.m.

Last Modified :

Aug. 28, 2026, 8:16 a.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products

The following products are affected by CVE-2026-80683 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

Solution
Update the Linux kernel to resolve a race condition leading to memory corruption.
  • Apply the Linux kernel patch for the Bluetooth SCO vulnerability.
  • Ensure the socket owns its connection reference.
  • Verify connection reference counting and ownership.
  • Update the system to the latest kernel version.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-80683.

URL Resource
https://git.kernel.org/stable/c/8fe627192fa5da7157f9a48608f13c04b6373e43
https://git.kernel.org/stable/c/a33bc07b4730b6cd5681ac77d18ae0de3e739690
https://git.kernel.org/stable/c/abd93c85c8667add738ee82aeab95dd9fc8265a2
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-80683 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-80683 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-80683 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-80683 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Aug. 28, 2026

    Action Type Old Value New Value
    Added 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.
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80683.json">CVE-2026-80683</a>
    Added Reference https://git.kernel.org/stable/c/8fe627192fa5da7157f9a48608f13c04b6373e43
    Added Reference https://git.kernel.org/stable/c/a33bc07b4730b6cd5681ac77d18ae0de3e739690
    Added Reference https://git.kernel.org/stable/c/abd93c85c8667add738ee82aeab95dd9fc8265a2
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.