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Linux KernelOperating system · Linux

CVE-2022-49077

MEDIUM · 5.5 CVSS v3.1 Published 2025-02-26
Fix available
A fix is available. Upgrade to 4.9.311 / 4.14.276 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:< 4.9.311>= 4.10, < 4.14.276>= 4.15, < 4.19.238>= 4.20, < 5.4.189>= 5.5, < 5.10.111>= 5.11, < 5.15.34>= 5.16, < 5.16.20>= 5.17, < 5.17.3= 5.18

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.9.311 / 4.14.276 / 4.19.238 or later
Fixed in 4.9.3114.14.2764.19.238
Vendor patch git.kernel.org →
Recommended fix High confidence

Linux Kernel 4.9.311, 4.14.276, 4.19.238, or 5.4.189 (depending on which branch you are on)

  1. Identify the currently running kernel version using 'uname -r' or 'cat /proc/version'
  2. Determine which version range your kernel falls into from the affected versions: < 4.9.311, >= 4.10 and < 4.14.276, >= 4.15 and < 4.19.238, or >= 4.20 and < 5.4.189
  3. Upgrade to a patched kernel version: For 4.9.x line, upgrade to 4.9.311 or later; For 4.14.x line, upgrade to 4.14.276 or later; For 4.19.x line, upgrade to 4.19.238 or later; For 5.4.x line, upgrade to 5.4.189 or later; For 5.10.x and later, the vulnerability was already fixed in later stable releases
  4. On Debian/Ubuntu: apt-get update && apt-get dist-upgrade, or install specific kernel package
  5. On RHEL/CentOS: yum update kernel
  6. On SuSE: zypper update kernel-default
  7. Reboot the system to load the fixed kernel
  8. Verify the fix is applied by checking the kernel version and reviewing the changelog for commit 01e67e04c28170c47700c2c226d732bbfedb1ad0
Caveat Kernel upgrades may require system reboot and could introduce compatibility issues with custom kernel modules or older drivers; ensure backup and test in non-production environment first

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-49077 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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