CVE-2025-40048: Linux kernel · uio_hv_generic: Let userspace take care of interrupt mask
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.5 High · fixed in 5.15.0-1100.107~20.04.2 : patch Linux kernel soon.
Data as of 28 Oct 2026, 11:19 UTC
- Patch
- Available – fixed in 5.15.0-1100.107~20.04.2, 5.15.0-1110.119~20.04.1, 5.15.0-1100.109~20.04.1 +71
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 28 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.
Patches and advisories
- ubuntu.com/security/notices/USN-8029-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8030-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8048-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-6 (opens in a new tab)
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 and fixed versions include Linux kernel releases 5.15.0-1094.97~20.04.1 and later. Users should update to these fixed kernel versions or later to resolve the issue. The fix removes driver-side interrupt mask changes except in set_event(), allowing userspace to control interrupt masking properly. No additional mitigation is required beyond applying the official kernel updates.
Description
CVE-2025-40048 is a vulnerability in the Linux kernel's uio_hv_generic driver where the driver incorrectly manages the interrupt mask instead of leaving this control entirely to userspace. This flaw can cause user-mode drivers to miss interrupts, leading to hangs when waiting on ring buffer events. The issue arises from a race condition between the driver and userspace manipulating the interrupt mask, causing pread() calls to wait indefinitely. The vulnerability has been fixed by removing driver-side interrupt mask changes except for one controlled instance, allowing userspace to manage interrupt masking properly.
References
- ubuntu.com/security/CVE-2025-40048 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40048 (opens in a new tab)
- git.kernel.org/linus/b15b7d2a1b09ef5428a8db260251897405a19496 (opens in a new tab)
- git.kernel.org/stable/c/01ce972e6f9974a7c76943bcb7e93746917db83a (opens in a new tab)
- git.kernel.org/stable/c/2af39ab5e6dc46b835a52e80a22d0cad430985e3 (opens in a new tab)
- git.kernel.org/stable/c/37bd91f22794dc05436130d6983302cb90ecfe7e (opens in a new tab)
- git.kernel.org/stable/c/a44f61f878f32071d6378e8dd7c2d47f9490c8f7 (opens in a new tab)
- git.kernel.org/stable/c/b15b7d2a1b09ef5428a8db260251897405a19496 (opens in a new tab)
- git.kernel.org/stable/c/e29587c07537929684faa365027f4b0d87521e1b (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8030-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8048-1 (opens in a new tab)