In the Linux kernel, the following vulnerability has been resolved:
dmaengine: idxd: Fix oops during rmmod on single-CPU platforms
During the removal of the idxd driver, registered offline callback is
invoked as part of the clean up process. However, on systems with only
one CPU online, no valid target is available to migrate the
perf context, resulting in a kernel oops:
BUG: unable to handle page fault for address: 000000000002a2b8
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 1470e1067 P4D 0
Oops: 0002 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 20 Comm: cpuhp/0 Not tainted 6.8.0-rc6-dsa+ #57
Hardware name: Intel Corporation AvenueCity/AvenueCity, BIOS BHSDCRB1.86B.2492.D03.2307181620 07/18/2023
RIP: 0010:mutex_lock+0x2e/0x50
...
Call Trace:
__die+0x24/0x70
page_fault_oops+0x82/0x160
do_user_addr_fault+0x65/0x6b0
__pfx___rdmsr_safe_on_cpu+0x10/0x10
exc_page_fault+0x7d/0x170
asm_exc_page_fault+0x26/0x30
mutex_lock+0x2e/0x50
mutex_lock+0x1e/0x50
perf_pmu_migrate_context+0x87/0x1f0
perf_event_cpu_offline+0x76/0x90 [idxd]
cpuhp_invoke_callback+0xa2/0x4f0
__pfx_perf_event_cpu_offline+0x10/0x10 [idxd]
cpuhp_thread_fun+0x98/0x150
smpboot_thread_fn+0x27/0x260
smpboot_thread_fn+0x1af/0x260
__pfx_smpboot_thread_fn+0x10/0x10
kthread+0x103/0x140
__pfx_kthread+0x10/0x10
ret_from_fork+0x31/0x50
__pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
Fix the issue by preventing the migration of the perf context to an
invalid target.
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 2026-10-25). 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, and whom BOD 26-04 binds: 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.
The score's inputs: 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