In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Only call get_timer_irq() once in constant_clockevent_init()
Under CONFIG_DEBUG_ATOMIC_SLEEP=y and CONFIG_DEBUG_PREEMPT=y, we can see
the following messages on LoongArch, this is because using might_sleep()
in preemption disable context.
[ 0.001127] smp: Bringing up secondary CPUs ...
[ 0.001222] Booting CPU#1...
[ 0.001244] 64-bit Loongson Processor probed (LA464 Core)
[ 0.001247] CPU1 revision is: 0014c012 (Loongson-64bit)
[ 0.001250] FPU1 revision is: 00000000
[ 0.001252] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:283
[ 0.001255] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1
[ 0.001257] preempt_count: 1, expected: 0
[ 0.001258] RCU nest depth: 0, expected: 0
[ 0.001259] Preemption disabled at:
[ 0.001261] [<9000000000223800>] arch_dup_task_struct+0x20/0x110
[ 0.001272] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.2.0-rc7+ #43
[ 0.001275] Hardware name: Loongson Loongson-3A5000-7A1000-1w-A2101/Loongson-LS3A5000-7A1000-1w-A2101, BIOS vUDK2018-LoongArch-V4.0.05132-beta10 12/13/202
[ 0.001277] Stack : 0072617764726148 0000000000000000 9000000000222f1c 90000001001e0000
[ 0.001286] 90000001001e3be0 90000001001e3be8 0000000000000000 0000000000000000
[ 0.001292] 90000001001e3be8 0000000000000040 90000001001e3cb8 90000001001e3a50
[ 0.001297] 9000000001642000 90000001001e3be8 be694d10ce4139dd 9000000100174500
[ 0.001303] 0000000000000001 0000000000000001 00000000ffffe0a2 0000000000000020
[ 0.001309] 000000000000002f 9000000001354116 00000000056b0000 ffffffffffffffff
[ 0.001314] 0000000000000000 0000000000000000 90000000014f6e90 9000000001642000
[ 0.001320] 900000000022b69c 0000000000000001 0000000000000000 9000000001736a90
[ 0.001325] 9000000100038000 0000000000000000 9000000000222f34 0000000000000000
[ 0.001331] 00000000000000b0 0000000000000004 0000000000000000 0000000000070000
[ 0.001337] ...
[ 0.001339] Call Trace:
[ 0.001342] [<9000000000222f34>] show_stack+0x5c/0x180
[ 0.001346] [<90000000010bdd80>] dump_stack_lvl+0x60/0x88
[ 0.001352] [<9000000000266418>] __might_resched+0x180/0x1cc
[ 0.001356] [<90000000010c742c>] mutex_lock+0x20/0x64
[ 0.001359] [<90000000002a8ccc>] irq_find_matching_fwspec+0x48/0x124
[ 0.001364] [<90000000002259c4>] constant_clockevent_init+0x68/0x204
[ 0.001368] [<900000000022acf4>] start_secondary+0x40/0xa8
[ 0.001371] [<90000000010c0124>] smpboot_entry+0x60/0x64
Here are the complete call chains:
smpboot_entry()
start_secondary()
constant_clockevent_init()
get_timer_irq()
irq_find_matching_fwnode()
irq_find_matching_fwspec()
mutex_lock()
might_sleep()
__might_sleep()
__might_resched()
In order to avoid the above issue, we should break the call chains,
using timer_irq_installed variable as check condition to only call
get_timer_irq() once in constant_clockevent_init() is a simple and
proper way.
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 low or medium mission impact; Track* at high (mission-essential systems).CISA 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 SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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)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