In the Linux kernel, the following vulnerability has been resolved:
stmmac: Clear variable when destroying workqueue
Currently when suspending driver and stopping workqueue it is checked whether
workqueue is not NULL and if so, it is destroyed.
Function destroy_workqueue() does drain queue and does clear variable, but
it does not set workqueue variable to NULL. This can cause kernel/module
panic if code attempts to clear workqueue that was not initialized.
This scenario is possible when resuming suspended driver in stmmac_resume(),
because there is no handling for failed stmmac_hw_setup(),
which can fail and return if DMA engine has failed to initialize,
and workqueue is initialized after DMA engine.
Should DMA engine fail to initialize, resume will proceed normally,
but interface won't work and TX queue will eventually timeout,
causing 'Reset adapter' error.
This then does destroy workqueue during reset process.
And since workqueue is initialized after DMA engine and can be skipped,
it will cause kernel/module panic.
To secure against this possible crash, set workqueue variable to NULL when
destroying workqueue.
Log/backtrace from crash goes as follows:
[88.031977]------------[ cut here ]------------
[88.031985]NETDEV WATCHDOG: eth0 (sxgmac): transmit queue 1 timed out
[88.032017]WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:477 dev_watchdog+0x390/0x398
[88.032251]---[ end trace e70de432e4d5c2c0 ]---
[88.032282]sxgmac 16d88000.ethernet eth0: Reset adapter.
[88.036359]------------[ cut here ]------------
[88.036519]Call trace:
[88.036523] flush_workqueue+0x3e4/0x430
[88.036528] drain_workqueue+0xc4/0x160
[88.036533] destroy_workqueue+0x40/0x270
[88.036537] stmmac_fpe_stop_wq+0x4c/0x70
[88.036541] stmmac_release+0x278/0x280
[88.036546] __dev_close_many+0xcc/0x158
[88.036551] dev_close_many+0xbc/0x190
[88.036555] dev_close.part.0+0x70/0xc0
[88.036560] dev_close+0x24/0x30
[88.036564] stmmac_service_task+0x110/0x140
[88.036569] process_one_work+0x1d8/0x4a0
[88.036573] worker_thread+0x54/0x408
[88.036578] kthread+0x164/0x170
[88.036583] ret_from_fork+0x10/0x20
[88.036588]---[ end trace e70de432e4d5c2c1 ]---
[88.036597]Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). 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
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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