In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Set hugetlb mmap base address aligned with pmd size
With ltp test case "testcases/bin/hugefork02", there is a dmesg error
report message such as:
kernel BUG at mm/hugetlb.c:5550!
Oops - BUG[#1]:
CPU: 0 UID: 0 PID: 1517 Comm: hugefork02 Not tainted 6.14.0-rc2+ #241
Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
pc 90000000004eaf1c ra 9000000000485538 tp 900000010edbc000 sp 900000010edbf940
a0 900000010edbfb00 a1 9000000108d20280 a2 00007fffe9474000 a3 00007ffff3474000
a4 0000000000000000 a5 0000000000000003 a6 00000000003cadd3 a7 0000000000000000
t0 0000000001ffffff t1 0000000001474000 t2 900000010ecd7900 t3 00007fffe9474000
t4 00007fffe9474000 t5 0000000000000040 t6 900000010edbfb00 t7 0000000000000001
t8 0000000000000005 u0 90000000004849d0 s9 900000010edbfa00 s0 9000000108d20280
s1 00007fffe9474000 s2 0000000002000000 s3 9000000108d20280 s4 9000000002b38b10
s5 900000010edbfb00 s6 00007ffff3474000 s7 0000000000000406 s8 900000010edbfa08
ra: 9000000000485538 unmap_vmas+0x130/0x218
ERA: 90000000004eaf1c __unmap_hugepage_range+0x6f4/0x7d0
PRMD: 00000004 (PPLV0 +PIE -PWE)
EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0)
PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
Process hugefork02 (pid: 1517, threadinfo=00000000a670eaf4, task=000000007a95fc64)
Call Trace:
[<90000000004eaf1c>] __unmap_hugepage_range+0x6f4/0x7d0
[<9000000000485534>] unmap_vmas+0x12c/0x218
[<9000000000494068>] exit_mmap+0xe0/0x308
[<900000000025fdc4>] mmput+0x74/0x180
[<900000000026a284>] do_exit+0x294/0x898
[<900000000026aa30>] do_group_exit+0x30/0x98
[<900000000027bed4>] get_signal+0x83c/0x868
[<90000000002457b4>] arch_do_signal_or_restart+0x54/0xfa0
[<90000000015795e8>] irqentry_exit_to_user_mode+0xb8/0x138
[<90000000002572d0>] tlb_do_page_fault_1+0x114/0x1b4
The problem is that base address allocated from hugetlbfs is not aligned
with pmd size. Here add a checking for hugetlbfs and align base address
with pmd size. After this patch the test case "testcases/bin/hugefork02"
passes to run.
This is similar to the commit 7f24cbc9c4d42db8a3c8484d1 ("mm/mmap: teach
generic_get_unmapped_area{_topdown} to handle hugetlb mappings").
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