In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: Fix use-after-free in tb_dp_dprx_work
The original code relies on cancel_delayed_work() in tb_dp_dprx_stop(),
which does not ensure that the delayed work item tunnel->dprx_work has
fully completed if it was already running. This leads to use-after-free
scenarios where tb_tunnel is deallocated by tb_tunnel_put(), while
tunnel->dprx_work remains active and attempts to dereference tb_tunnel
in tb_dp_dprx_work().
A typical race condition is illustrated below:
CPU 0 | CPU 1
tb_dp_tunnel_active() |
tb_deactivate_and_free_tunnel()| tb_dp_dprx_start()
tb_tunnel_deactivate() | queue_delayed_work()
tb_dp_activate() |
tb_dp_dprx_stop() | tb_dp_dprx_work() //delayed worker
cancel_delayed_work() |
tb_tunnel_put(tunnel); |
| tunnel = container_of(...); //UAF
| tunnel-> //UAF
Replacing cancel_delayed_work() with cancel_delayed_work_sync() is
not feasible as it would introduce a deadlock: both tb_dp_dprx_work()
and the cleanup path acquire tb->lock, and cancel_delayed_work_sync()
would wait indefinitely for the work item that cannot proceed.
Instead, implement proper reference counting:
- If cancel_delayed_work() returns true (work is pending), we release
the reference in the stop function.
- If it returns false (work is executing or already completed), the
reference is released in delayed work function itself.
This ensures the tb_tunnel remains valid during work item execution
while preventing memory leaks.
This bug was found by static analysis.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
- EG Severity
- Not assessed: no CVSS publishedA missing CVSS is not a severity of zero.
- EG Likelihood
- 0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- No SSVC decision: EchelonGraph has not assessed this CVECISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the BOD 26-04 block below.
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it