Description
In the Linux kernel, the following vulnerability has been resolved:
ptp: vmclock: prevent read-only mappings from becoming writable
vmclock_miscdev_mmap() rejects writable mappings of the shared vmclock ABI page with -EROFS, but leaves VM_MAYWRITE set. Userspace can map the page read-only and then upgrade it to writable with mprotect(), after which the guest can corrupt the host-written timekeeping data (sequence counter, UTC time, TSC offset) that the vmclock ABI defines as read-only.
Clear VM_MAYWRITE on the read-only path so the mapping cannot be upgraded, as i915 does for its read-only objects and as fixed in drm/vc4 (CVE-2026-68445) and drm/panthor (CVE-2024-53071).
Metrics
CVSS 3.1 8.8/10
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HAffected software
Source: the vendor's advisory (CNA). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= 20503272422693d793b84f88bf23fe4e955d3a33, < 5b4f2bec7bea6c04084d720d731bedee7caf878d; >= 20503272422693d793b84f88bf23fe4e955d3a33, < 3f5677d2f817355147337f0453174c7bb0f3b66a; >= 20503272422693d793b84f88bf23fe4e955d3a33, < 2496e141827102d6af512950057d402a2cfb2bfc; >= 20503272422693d793b84f88bf23fe4e955d3a33, < 2e596e7814ba38cdc129991058b6c254ed37cb11; >= 20503272422693d793b84f88bf23fe4e955d3a33, < 0ce59c4148ecd1520c5592a63bb3c8991ee2d326; >= 20503272422693d793b84f88bf23fe4e955d3a33, < a5edadbae57e2298a56cf7a4e774a027905a331f |
| Linux | Linux | 6.13 |
References
- https://git.kernel.org/stable/c/0ce59c4148ecd1520c5592a63bb3c8991ee2d326
- https://git.kernel.org/stable/c/2496e141827102d6af512950057d402a2cfb2bfc
- https://git.kernel.org/stable/c/2e596e7814ba38cdc129991058b6c254ed37cb11
- https://git.kernel.org/stable/c/3f5677d2f817355147337f0453174c7bb0f3b66a
- https://git.kernel.org/stable/c/5b4f2bec7bea6c04084d720d731bedee7caf878d
- https://git.kernel.org/stable/c/a5edadbae57e2298a56cf7a4e774a027905a331f
Timeline
- Published
- Aug 28, 2026
- Last modified
- Oct 19, 2026
- NVD status
- Received