GHSA-66mv-wq2c-77c3HighCVSS 8.8
In the Linux kernel, the following vulnerability has been resolved: ptp: vmclock: prevent read...
🔗 CVE IDs covered (1)
📋 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).
🔗 References (5)
- https://nvd.nist.gov/vuln/detail/CVE-2026-80724
- https://git.kernel.org/stable/c/2496e141827102d6af512950057d402a2cfb2bfc
- https://git.kernel.org/stable/c/2e596e7814ba38cdc129991058b6c254ed37cb11
- https://git.kernel.org/stable/c/5b4f2bec7bea6c04084d720d731bedee7caf878d
- https://github.com/advisories/GHSA-66mv-wq2c-77c3