CyberSecBulletin
CVE-2024-27022NVD status: Modified

Linux: Use of Uninitialized Resource

Published Updated By the CyberSecBulletin desk

CVE-2024-27022 is a high-severity use of uninitialized resource vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 087de0e15e6830ed630c793fa4bebd62e8348da1, 2e5cbab8ccbfc7d4a3d8a21d3c2a1f2c1aa29b5b, abdb88dd272bbeb93efe01d8e0b7b17e24af3a34 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.27% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 087de0e15e6830ed630c793fa4bebd62e8348da1 or 2e5cbab8ccbfc7d4a3d8a21d3c2a1f2c1aa29b5b or abdb88dd272bbeb93efe01d8e0b7b17e24af3a34 or 35e351780fa9d8240dd6f7e4f245f9ea37e96c19, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.1.90 or 6.6.30 or 6.8.8, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux8d9bfb2608145cf3e408428c224099e1585471af up to, but not including, 087de0e15e6830ed630c793fa4bebd62e8348da1; 8d9bfb2608145cf3e408428c224099e1585471af up to, but not including, 2e5cbab8ccbfc7d4a3d8a21d3c2a1f2c1aa29b5b; 8d9bfb2608145cf3e408428c224099e1585471af up to, but not including, abdb88dd272bbeb93efe01d8e0b7b17e24af3a34; 8d9bfb2608145cf3e408428c224099e1585471af up to, but not including, 35e351780fa9d8240dd6f7e4f245f9ea37e96c19; 6.1087de0e15e6830ed630c793fa4bebd62e8348da1, 2e5cbab8ccbfc7d4a3d8a21d3c2a1f2c1aa29b5b, abdb88dd272bbeb93efe01d8e0b7b17e24af3a34, 35e351780fa9d8240dd6f7e4f245f9ea37e96c19
LinuxLinux Kernel6.1 up to, but not including, 6.1.90; 6.2 up to, but not including, 6.6.30; 6.7 up to, but not including, 6.8.8; 6.96.1.90, 6.6.30, 6.8.8

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: fork: defer linking file vma until vma is fully initialized Thorvald reported a WARNING [1]. And the root cause is below race: CPU 1 CPU 2 fork hugetlbfs_fallocate dup_mmap hugetlbfs_punch_hole i_mmap_lock_write(mapping); vma_interval_tree_insert_after -- Child vma is visible through i_mmap tree. i_mmap_unlock_write(mapping); hugetlb_dup_vma_private -- Clear vma_lock outside i_mmap_rwsem! i_mmap_lock_write(mapping); hugetlb_vmdelete_list vma_interval_tree_foreach hugetlb_vma_trylock_write -- Vma_lock is cleared. tmp->vm_ops->open -- Alloc new vma_lock outside i_mmap_rwsem! hugetlb_vma_unlock_write -- Vma_lock is assigned!!! i_mmap_unlock_write(mapping); hugetlb_dup_vma_private() and hugetlb_vm_op_open() are called outside i_mmap_rwsem lock while vma lock can be used in the same time. Fix this by deferring linking file vma until vma is fully initialized. Those vmas should be initialized first before they can be used.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use of Uninitialized Resource

The product uses or accesses a resource that has not been initialized.

How developers prevent this class of flaw

  • Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.
  • Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
  • Avoid race conditions (CWE-362) during initialization routines.

More Use of Uninitialized Resource vulnerabilities (CWE-908)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use of Uninitialized Resource vulnerabilities

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