ptp: vmclock: prevent read-only mappings from becoming writable
41Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 8.8epss 0.1%
from disclosure to weapon2 days
Published on NVDAug 28
1st PoC+2d
exploitation probability
0.1%top 98% of all CVEs
observed exploitation
nono source reports it
1 public exploit(s)
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).
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Affected products
Linux · Linuxpublic PoCs found — 1
githubgithub.com/suruurism/cve-writeups-and-pocs★ 1⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.