Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2025-37893: LoongArch: BPF: Fix off-by-one error in build_prologue()

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.28% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 205a2182c51ffebaef54d643e3745e720cded08b, 48b904de2408af5f936f0e03f48dfcddeab58aa0, 7e2586991e36663c9bc48c828b83eab180ad30a9; azl3 kernel 6.6.85.1-4 on Azure Linux 3.0 6.6.92.2-1; azl3 kernel 6.6.92.2-1 on Azure Linux 3.0 6.6.92.2-1.
  • Severity is disputed: the assigning authority (CNA) scores it 7.8, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 205a2182c51ffebaef54d643e3745e720cded08b, 48b904de2408af5f936f0e03f48dfcddeab58aa0, 7e2586991e36663c9bc48c828b83eab180ad30a9; azl3 kernel 6.6.85.1-4 on Azure Linux 3.0 6.6.92.2-1; azl3 kernel 6.6.92.2-1 on Azure Linux 3.0 6.6.92.2-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Fix off-by-one error in build_prologue() Vincent reported that running BPF progs with tailcalls on LoongArch causes kernel hard lockup. Debugging the issues shows that the JITed image missing a jirl instruction at the end of the epilogue. There are two passes in JIT compiling, the first pass set the flags and the second pass generates JIT code based on those flags. With BPF progs mixing bpf2bpf and tailcalls, build_prologue() generates N insns in the first pass and then generates N+1 insns in the second pass. This makes epilogue_offset off by one and we will jump to some unexpected insn and cause lockup. Fix this by inserting a nop insn.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Apr 18, 2025
Updated
Aug 5, 2026
EPSS
0.2% · 20th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.5
CNA · Linux
7.8
2.3 point gap

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-37893

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.1 and later · before 6.1.134
  • linux linux kernel6.2 and later · before 6.6.87
  • linux linux kernel6.7 and later · before 6.12.23
  • linux linux kernel6.13 and later · before 6.13.11
  • linux linux kernel6.14 and later · before 6.14.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.1affected
    • 5dc615520c4dfb358245680f1904bad61116648e and later · before b3ffad2f02db4aace6799fe0049508b8925eae45affected · git
    • 5dc615520c4dfb358245680f1904bad61116648e and later · before 205a2182c51ffebaef54d643e3745e720cded08baffected · git
    • 5dc615520c4dfb358245680f1904bad61116648e and later · before c74d95a5679741ef428974ab788f5b0758dc78aeaffected · git
    • 5dc615520c4dfb358245680f1904bad61116648e and later · before 48b904de2408af5f936f0e03f48dfcddeab58aa0affected · git
    • 5dc615520c4dfb358245680f1904bad61116648e and later · before 7e2586991e36663c9bc48c828b83eab180ad30a9affected · git
    • before 6.1not affected · semver
    • 6.6.87 and later · up to and including 6.6.*not affected · semver
    • 6.12.23 and later · up to and including 6.12.*not affected · semver
    • 6.13.11 and later · up to and including 6.13.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.25-16.12.25-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2021-47670Apr 17, 2025 · can: peak_usb: fix use after free bugs
    35Monitor
  • ← EarlierCVE-2021-47671Apr 17, 2025 · can: etas_es58x: es58x_rx_err_msg(): fix memory leak in error path
    13Monitor
  • Later →CVE-2025-37925Apr 18, 2025 · jfs: reject on-disk inodes of an unsupported type
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux205a2182c51ffebaef54d643e3745e720cded08bVendor (CNA)
Linux Linux48b904de2408af5f936f0e03f48dfcddeab58aa0Vendor (CNA)
Linux Linux7e2586991e36663c9bc48c828b83eab180ad30a9Vendor (CNA)
Linux Linuxb3ffad2f02db4aace6799fe0049508b8925eae45Vendor (CNA)
Linux Linuxc74d95a5679741ef428974ab788f5b0758dc78aeVendor (CNA)
azl3 kernel 6.6.85.1-4 on Azure Linux 3.06.6.92.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.92.2-1 on Azure Linux 3.06.6.92.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.12.25-1 · Debian:13Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-53088432 days apartnet: bcmgenet: fix off-by-one in bcmgenet_put_txcb
    39Monitor
  • CVE-2026-53309434 days apartocfs2/dlm: fix off-by-one in dlm_match_regions() region comparison
    39Monitor
  • CVE-2026-64047457 days apartnet: tls: fix off-by-one in sg_chain entry count for wrapped sk_msg ring
    39Monitor
  • CVE-2024-5799051 days apartwifi: mt76: mt7925: fix off by one in mt7925_load_clc()
    31Monitor
  • CVE-2024-47682179 days apartscsi: sd: Fix off-by-one error in sd_read_block_characteristics()
    31Monitor
  • CVE-2024-49880179 days apartext4: fix off by one issue in alloc_flex_gd()
    31Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-193 · Off-by-one Error

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records