Linux Kernel up to 6.12.108/6.18.49/7.2.3 ring-buffer ring_buffer_read_page/ring_buffer_read_start race condition

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$0-$5k0.00+

Summaryinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.12.108/6.18.49/7.2.3. The affected element is the function ring_buffer_read_page/ring_buffer_read_start of the component ring-buffer. Executing a manipulation can lead to race condition. This vulnerability appears as CVE-2026-89771. The attack may be performed from remote. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.12.108/6.18.49/7.2.3 and classified as very critical. This vulnerability affects the function ring_buffer_read_page/ring_buffer_read_start of the component ring-buffer. The manipulation with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix subbuf resize race with ring buffer readers trace_buffer subbuf_size is read lockless in ring_buffer_read_page() and ring_buffer_read_start(), while it can simultaneously be resized with ring_buffer_subbuf_order_set(). Instead of trace_buffer::subbuf_size, use bpage::order in ring_buffer_read_start() and ring_buffer_read_page(). In ring_buffer_read_start(), even with resize_disabled, there is still a possibility of a race with a buffer modification. Hold the trace_buffer mutex to synchronise with any pending ring buffer order modification. trace_buffer::subbuf_size is now actually useless, remove it. Also, create accessors rb_subbuf_capacity() and rb_page_capacity() which return the actual size available for storing events, while rb_subbuf_size() returns the actual subbuf page-size.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-89771 since 09/11/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/11/2026).

Upgrading to version 6.12.109, 6.18.50, 7.2.4 or 7.3-rc1 eliminates this vulnerability. Applying the patch 6d666f0b8b36c0765cf19fbe6de5a7ba5a73aad9/50f4a793c4ff24826efb0ac700989a5063cc53df/0c7c517827a453128a8f58bfd849546a29813b27/8a5f63637890f03177146efddaba5ec7a1b4d61f is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Once again VulDB remains the best source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.109/6.18.50/7.2.4/7.3-rc1
Patch: 6d666f0b8b36c0765cf19fbe6de5a7ba5a73aad9/50f4a793c4ff24826efb0ac700989a5063cc53df/0c7c517827a453128a8f58bfd849546a29813b27/8a5f63637890f03177146efddaba5ec7a1b4d61f

Timelineinfo

09/11/2026 Advisory disclosed
09/11/2026 +0 days CVE reserved
09/11/2026 +0 days VulDB entry created
09/11/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89771 (🔒)
GCVE (CVE): GCVE-0-2026-89771
GCVE (VulDB): GCVE-100-402628

Entryinfo

Created: 09/11/2026 23:08
Changes: 09/11/2026 23:08 (59)
Complete: 🔍
Cache ID: 216::103

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