Linux: NULL Pointer Dereference
CVE-2024-26672 is a high-severity NULL pointer dereference vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 7b5d58c07024516c0e81b95e98f37710cf402c53, 4f32504a2f85a7b40fe149436881381f48e9c0c0 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 0.22% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 7b5d58c07024516c0e81b95e98f37710cf402c53 or 4f32504a2f85a7b40fe149436881381f48e9c0c0, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.7.4 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | d38ceaf99ed015f2a0b9af3499791bd3a3daae21 up to, but not including, 7b5d58c07024516c0e81b95e98f37710cf402c53; d38ceaf99ed015f2a0b9af3499791bd3a3daae21 up to, but not including, 4f32504a2f85a7b40fe149436881381f48e9c0c0; 4.2 | 7b5d58c07024516c0e81b95e98f37710cf402c53, 4f32504a2f85a7b40fe149436881381f48e9c0c0 |
| Linux | Linux Kernel | before 6.7.4 | 6.7.4 |
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
- NoneNothing can be modified.
- 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:N/A:H. Scored by CISA (ADP).
Official description
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix variable 'mca_funcs' dereferenced before NULL check in 'amdgpu_mca_smu_get_mca_entry()' Fixes the below: drivers/gpu/drm/amd/amdgpu/amdgpu_mca.c:377 amdgpu_mca_smu_get_mca_entry() warn: variable dereferenced before check 'mca_funcs' (see line 368) 357 int amdgpu_mca_smu_get_mca_entry(struct amdgpu_device *adev, enum amdgpu_mca_error_type type, 358 int idx, struct mca_bank_entry *entry) 359 { 360 const struct amdgpu_mca_smu_funcs *mca_funcs = adev->mca.mca_funcs; 361 int count; 362 363 switch (type) { 364 case AMDGPU_MCA_ERROR_TYPE_UE: 365 count = mca_funcs->max_ue_count; mca_funcs is dereferenced here. 366 break; 367 case AMDGPU_MCA_ERROR_TYPE_CE: 368 count = mca_funcs->max_ce_count; mca_funcs is dereferenced here. 369 break; 370 default: 371 return -EINVAL; 372 } 373 374 if (idx >= count) 375 return -EINVAL; 376 377 if (mca_funcs && mca_funcs->mca_get_mca_entry) ^^^^^^^^^ Checked too late!
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
How developers prevent this class of flaw
- For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
- Select a programming language that is not susceptible to these issues.
- Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent NULL Pointer Dereference vulnerabilities
- 7.4 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
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