NVD / CVE Program· CNA Linux

CVE-2024-26983: bootconfig: use memblock_free_late to free xbc memory to buddy

HighCVSS 7.8 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 31/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.23% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 1e7feb31a18c197d63a5e606025ed63c762f8918, 5a7dfb8fcd3f29fc93161100179b27f24f3d5f35, 89f9a1e876b5a7ad884918c03a46831af202c8a0; azl3 hyperv-daemons 6.6.22.1-2 on Azure Linux 3.0 6.6.35.1-1; azl3 hyperv-daemons 6.6.35.1-1 on Azure Linux 3.0 6.6.35.1-1.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 1e7feb31a18c197d63a5e606025ed63c762f8918, 5a7dfb8fcd3f29fc93161100179b27f24f3d5f35, 89f9a1e876b5a7ad884918c03a46831af202c8a0; azl3 hyperv-daemons 6.6.22.1-2 on Azure Linux 3.0 6.6.35.1-1; azl3 hyperv-daemons 6.6.35.1-1 on Azure Linux 3.0 6.6.35.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: bootconfig: use memblock_free_late to free xbc memory to buddy On the time to free xbc memory in xbc_exit(), memblock may has handed over memory to buddy allocator. So it doesn't make sense to free memory back to memblock. memblock_free() called by xbc_exit() even causes UAF bugs on architectures with CONFIG_ARCH_KEEP_MEMBLOCK disabled like x86. Following KASAN logs shows this case. This patch fixes the xbc memory free problem by calling memblock_free() in early xbc init error rewind path and calling memblock_free_late() in xbc exit path to free memory to buddy allocator. [ 9.410890] ================================================================== [ 9.418962] BUG: KASAN: use-after-free in memblock_isolate_range+0x12d/0x260 [ 9.426850] Read of size 8 at addr ffff88845dd30000 by task swapper/0/1 [ 9.435901] CPU: 9 PID: 1 Comm: swapper/0 Tainted: G U 6.9.0-rc3-00208-g586b5dfb51b9 #5 [ 9.446403] Hardware name: Intel Corporation RPLP LP5 (CPU:RaptorLake)/RPLP LP5 (ID:13), BIOS IRPPN02.01.01.00.00.19.015.D-00000000 Dec 28 2023 [ 9.460789] Call Trace: [ 9.463518] <TASK> [ 9.465859] dump_stack_lvl+0x53/0x70 [ 9.469949] print_report+0xce/0x610 [ 9.473944] ? __virt_addr_valid+0xf5/0x1b0 [ 9.478619] ? memblock_isolate_range+0x12d/0x260 [ 9.483877] kasan_report+0xc6/0x100 [ 9.487870] ? memblock_isolate_range+0x12d/0x260 [ 9.493125] memblock_isolate_range+0x12d/0x260 [ 9.498187] memblock_phys_free+0xb4/0x160 [ 9.502762] ? __pfx_memblock_phys_free+0x10/0x10 [ 9.508021] ? mutex_unlock+0x7e/0xd0 [ 9.512111] ? __pfx_mutex_unlock+0x10/0x10 [ 9.516786] ? kernel_init_freeable+0x2d4/0x430 [ 9.521850] ? __pfx_kernel_init+0x10/0x10 [ 9.526426] xbc_exit+0x17/0x70 [ 9.529935] kernel_init+0x38/0x1e0 [ 9.533829] ? _raw_spin_unlock_irq+0xd/0x30 [ 9.538601] ret_from_fork+0x2c/0x50 [ 9.542596] ? __pfx_kernel_init+0x10/0x10 [ 9.547170] ret_from_fork_asm+0x1a/0x30 [ 9.551552] </TASK> [ 9.555649] The buggy address belongs to the physical page: [ 9.561875] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x45dd30 [ 9.570821] flags: 0x200000000000000(node=0|zone=2) [ 9.576271] page_type: 0xffffffff() [ 9.580167] raw: 0200000000000000 ffffea0011774c48 ffffea0012ba1848 0000000000000000 [ 9.588823] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 [ 9.597476] page dumped because: kasan: bad access detected [ 9.605362] Memory state around the buggy address: [ 9.610714] ffff88845dd2ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 9.618786] ffff88845dd2ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 9.626857] >ffff88845dd30000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 9.634930] ^ [ 9.638534] ffff88845dd30080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 9.646605] ffff88845dd30100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 9.654675] ==================================================================

Memory safety

Published: May 1, 2024
Updated: Aug 5, 2026
EPSS: 0.2% · 14th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 7.8
CNA · Linux: 7.8; agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

linux linux kernel5.15 and later · before 6.1.88
linux linux kernel6.2 and later · before 6.6.29
linux linux kernel6.7 and later · before 6.8.8
linux linux kernel6.9

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 5.15affected
- 40caa127f3c7279c75cb0c9684559fa314ee3a66 and later · before 1e7feb31a18c197d63a5e606025ed63c762f8918affected · git
- 40caa127f3c7279c75cb0c9684559fa314ee3a66 and later · before e46d3be714ad9652480c6db129ab8125e2d20ab7affected · git
- 40caa127f3c7279c75cb0c9684559fa314ee3a66 and later · before 5a7dfb8fcd3f29fc93161100179b27f24f3d5f35affected · git
- 40caa127f3c7279c75cb0c9684559fa314ee3a66 and later · before 89f9a1e876b5a7ad884918c03a46831af202c8a0affected · git
- before 5.15not affected · semver
- 6.1.88 and later · up to and including 6.1.*not affected · semver
- 6.6.29 and later · up to and including 6.6.*not affected · semver
- 6.8.8 and later · up to and including 6.8.*not affected · semver
- 6.9 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.90-1	6.1.90-1
Debian:13	linux	before 6.8.9-1	6.8.9-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
90Now
CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
89Now
CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
85Now

Published before and after this one in the same product

← EarlierCVE-2024-26980May 1, 2024 · ksmbd: fix slab-out-of-bounds in smb2_allocate_rsp_buf
32Monitor
← EarlierCVE-2024-26981May 1, 2024 · nilfs2: fix OOB in nilfs_set_de_type
31Monitor
Later →CVE-2024-26984May 1, 2024 · nouveau: fix instmem race condition around ptr stores
22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	1e7feb31a18c197d63a5e606025ed63c762f8918	Vendor (CNA)
Linux Linux	5a7dfb8fcd3f29fc93161100179b27f24f3d5f35	Vendor (CNA)
Linux Linux	89f9a1e876b5a7ad884918c03a46831af202c8a0	Vendor (CNA)
Linux Linux	e46d3be714ad9652480c6db129ab8125e2d20ab7	Vendor (CNA)
azl3 hyperv-daemons 6.6.22.1-2 on Azure Linux 3.0	6.6.35.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
azl3 hyperv-daemons 6.6.35.1-1 on Azure Linux 3.0	6.6.35.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.90-1 · Debian:12	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-24-0387 · May 2, 2024(Linux Kernel Güncellemesi)

All national notices →

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/1e7feb31a18c197d63a5e606025ed63c762f8918

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records