CVE-2022-49077: In the Linux kernel, the following vulnerability has been resolved: mmmremap.c: avoid pointless invalidate_range_start/end on mremap(old_size=0) If ...

Description

In the Linux kernel, the following vulnerability has been resolved: mmmremap.c: avoid pointless invalidate_range_start/end on mremap(old_size=0) If an mremap() syscall with old_size=0 ends up in move_page_tables(), it will call invalidate_range_start()/invalidate_range_end() unnecessarily, i.e. with an empty range. This causes a WARN in KVM's mmu_notifier. In the past, empty ranges have been diagnosed to be off-by-one bugs, hence the WARNing. Given the low (so far) number of unique reports, the benefits of detecting more buggy callers seem to outweigh the cost of having to fix cases such as this one, where userspace is doing something silly. In this particular case, an early return from move_page_tables() is enough to fix the issue.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.23%

13.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-193

Affected Software

Vendor	Product	Versions	Update
Linux	Linux Kernel	< 4.9.311	—
Linux	Linux Kernel	>= 4.10, < 4.14.276	—
Linux	Linux Kernel	>= 4.15, < 4.19.238	—
Linux	Linux Kernel	>= 4.20, < 5.4.189	—
Linux	Linux Kernel	>= 5.5, < 5.10.111	—
Linux	Linux Kernel	>= 5.11, < 5.15.34	—
Linux	Linux Kernel	>= 5.16, < 5.16.20	—
Linux	Linux Kernel	>= 5.17, < 5.17.3	—
Linux	Linux Kernel	5.18	Rc1

References

Timeline

Published: Feb 26, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2022-49077?

In the Linux kernel, the following vulnerability has been resolved: mmmremap.c: avoid pointless invalidate_range_start/end on mremap(old_size=0) If an mremap() syscall with old_size=0 ends up in move_page_tables(), it will call invalidate_range_start()/invalidate_range_end() unnecessarily, i.e. with an empty range. This causes a WARN in KVM's mmu_notifier. In the past, empty ranges have been diagnosed to be off-by-one bugs, hence the WARNing. Given the low (so far) number of unique reports, the benefits of detecting more buggy callers seem to outweigh the cost of having to fix cases such as this one, where userspace is doing something silly. In this particular case, an early return from move_page_tables() is enough to fix the issue.

How severe is CVE-2022-49077?

CVE-2022-49077 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.

How do I fix CVE-2022-49077?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.