Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Use __try_cmpxchg_user() to update guest PTE A/D bits Use the recently introduced __try_cmpxchg_user() to update guest PTE A/D bits instead of mapping the PTE into kernel address space. The VM_PFNMAP path is broken as it assumes that vm_pgoff is the base pfn of the mapped VMA range, which is conceptually wrong as vm_pgoff is the offset relative to the file and has nothing to do with the pfn. The horrific hack worked for the original use case (backing guest memory with /dev/mem), but leads to accessing "random" pfns for pretty much any other VM_PFNMAP case.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 5.2, < 5.17.13 |
References
- https://git.kernel.org/stable/c/38b888911e8dc89b89d8147cfb1d2dbe6373bf78Patch
- https://git.kernel.org/stable/c/8089e5e1d18402fb8152d6b6815450a36fffa9b0Patch
- https://git.kernel.org/stable/c/f122dfe4476890d60b8c679128cd2259ec96a24cPatch
FAQ
What is CVE-2022-49562?
CVE-2022-49562 is a vulnerability with a CVSS score of 5.5 (MEDIUM). In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Use __try_cmpxchg_user() to update guest PTE A/D bits Use the recently introduced __try_cmpxchg_user() to update guest P...
How severe is CVE-2022-49562?
CVE-2022-49562 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2022-49562?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.