CVE-2026-80724

Summary

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).

Affected Software

VendorProductVersion RangeStatus
LinuxLinux20503272422693d793b84f88bf23fe4e955d3a33 < 5b4f2bec7bea6c04084d720d731bedee7caf878daffected
LinuxLinux20503272422693d793b84f88bf23fe4e955d3a33 < 3f5677d2f817355147337f0453174c7bb0f3b66aaffected
LinuxLinux20503272422693d793b84f88bf23fe4e955d3a33 < 2496e141827102d6af512950057d402a2cfb2bfcaffected
LinuxLinux20503272422693d793b84f88bf23fe4e955d3a33 < 2e596e7814ba38cdc129991058b6c254ed37cb11affected
LinuxLinux20503272422693d793b84f88bf23fe4e955d3a33 < 0ce59c4148ecd1520c5592a63bb3c8991ee2d326affected
LinuxLinux20503272422693d793b84f88bf23fe4e955d3a33 < a5edadbae57e2298a56cf7a4e774a027905a331faffected
LinuxLinux6.13affected
LinuxLinux0 < 6.13unaffected
LinuxLinux6.18.47 <= 6.18.*unaffected
LinuxLinux6.18.50 <= 6.18.*unaffected
LinuxLinux7.1.11 <= 7.1.*unaffected
LinuxLinux7.2.1 <= 7.2.*unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References