CVE-2025-39704 — LoongArch: KVM: Fix stack protector issue in send_ipi_data()
In the Linux kernel, the following vulnerability has been resolved: LoongArch: KVM: Fix stack protector issue in send_ipi_data() Function kvm_io_bus_read() is called in function send_ipi_data(), buffer size of parameter *val should be at least 8 bytes. Since some emulation functions like loongarch_ipi_readl() and kvm_eiointc_read() will write the buffer *val with 8 bytes signed extension regardless parameter len. Otherwise there will be buffer overflow issue when CONFIG_STACKPROTECTOR is enabled. The bug report is shown as follows: Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: send_ipi_data+0x194/0x1a0 [kvm] CPU: 11 UID: 107 PID: 2692 Comm: CPU 0/KVM Not tainted 6.17.0-rc1+ #102 PREEMPT(full) Stack : 9000000005901568 0000000000000000 9000000003af371c 900000013c68c000 900000013c68f850 900000013c68f858 0000000000000000 900000013c68f998 900000013c68f990 900000013c68f990 900000013c68f6c0 fffffffffffdb058 fffffffffffdb0e0 900000013c68f858 911e1d4d39cf0ec2 9000000105657a00 0000000000000001 fffffffffffffffe 0000000000000578 282049464555206e 6f73676e6f6f4c20 0000000000000001 00000000086b4000 0000000000000000 0000000000000000 0000000000000000 9000000005709968 90000000058f9000 900000013c68fa68 900000013c68fab4 90000000029279f0 900000010153f940 900000010001f360 0000000000000000 9000000003af3734 000000004390000c 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1d ... Call Trace: [<9000000003af3734>] show_stack+0x5c/0x180 [<9000000003aed168>] dump_stack_lvl+0x6c/0x9c [<9000000003ad0ab0>] vpanic+0x108/0x2c4 [<9000000003ad0ca8>] panic+0x3c/0x40 [<9000000004eb0a1c>] __stack_chk_fail+0x14/0x18 [<ffff8000023473f8>] send_ipi_data+0x190/0x1a0 [kvm] [<ffff8000023313e4>] __kvm_io_bus_write+0xa4/0xe8 [kvm] [<ffff80000233147c>] kvm_io_bus_write+0x54/0x90 [kvm] [<ffff80000233f9f8>] kvm_emu_iocsr+0x180/0x310 [kvm] [<ffff80000233fe08>] kvm_handle_gspr+0x280/0x478 [kvm] [<ffff8000023443e8>] kvm_handle_exit+0xc0/0x130 [kvm]
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ daee2f9cae5510ba1bd9eed6b0cf0ca8dc276118 and < b5b49d341f90eed6de794b6ff34ad3dd66d34343≥ daee2f9cae5510ba1bd9eed6b0cf0ca8dc276118 and < 5c68549c81bcca70fc464e305ffeefd9af968287version 6.13 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 6.13 and < 6.16.4version 6.17-rc1version 6.17-rc2 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.8 | CVSS 3.1 | High | 2.0 | 6.0 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 8.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
| 5.5 | CVSS 3.1 | Medium | 1.8 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 5.5 | CVSS 3.1 | Medium | — | — | GitHub, Inc. via GitHub Security Advisories |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- Affected products added · linux/linux kernel
- CVSS changed · 5.5
- Source status changed · → Modified
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 19, 2026 – Oct 19, 2026
- 1× Official description updated · Oct 19, 2026 – Oct 19, 2026
References
4 on the record
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-98866 sched/cache: Introduce task_struct->sched_cache_grp to fix UAF 1d
- Unknown CVE-2026-98867 dm-pcache: bound the logical key offset from persistent memory 1d
- Unknown CVE-2026-98868 dm-pcache: reject a kset that overruns its segment 1d
- Unknown CVE-2026-98856 kprobes: Skip disarmed probes when checking optkprobe overlap 1d
- Unknown CVE-2026-98857 ipvs: bound LBLCR and LBLC cache growth 1d
- Unknown CVE-2026-98858 io_uring: fix task_work add use-after-free with SQPOLL 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2025-39704 is "LoongArch: KVM: Fix stack protector issue in send_ipi_data()", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.15% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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