CVE-2025-40012: Linux kernel · net/smc: fix warning in smc_rx_splice() when calling get_page()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 6.17.0-6.6 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.17.0-6.6, 6.17.0-1003.3, 6.17.0-1006.6 +3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available that replaces the memory allocation method to ensure page-backed buffers, eliminating the use-after-free risk. Users should apply the official Linux kernel updates that include this fix. No additional mitigation is required beyond applying the patch.
Description
A use-after-free vulnerability in the Linux kernel's SMC (Shared Memory Communications) subsystem was resolved by changing memory allocation from kmalloc() to folio_alloc() to ensure page-backed memory. The issue occurs because kmalloc memory is not page-backed, triggering warnings and preventing proper reference counting, which can lead to use-after-free if the memory is released prematurely. This vulnerability affects multiple Linux kernel versions prior to 6.17.0-6.6 and specific older versions. A fix is available.
References
- ubuntu.com/security/CVE-2025-40012 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40012 (opens in a new tab)
- git.kernel.org/linus/a35c04de2565db191726b5741e6b66a35002c652 (opens in a new tab)
- git.kernel.org/stable/c/14fc4fdae42e34d7ee871b292ac2ecc61c2c5de7 (opens in a new tab)
- git.kernel.org/stable/c/a35c04de2565db191726b5741e6b66a35002c652 (opens in a new tab)
- git.kernel.org/stable/c/d5411685dc2f6ac7bdf01a0a204d56cae38c6cf6 (opens in a new tab)