In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()… (CVE-2026-89503)
A race condition vulnerability in the Linux kernel's ring buffer subsystem was resolved. The issue involves a race between ring_buffer_alloc_read_page() and ring_buffer_subbuf_order_set, which can cause allocation of a reader page with an outdated or mismatched order. This mismatch can lead to inconsistencies in memory allocation for the ring buffer reader page. The fix ensures that the allocation uses the correct order value to prevent this race condition.
AI Analysis
Technical Summary
The Linux kernel contained a race condition in the ring buffer code where ring_buffer_alloc_read_page() could allocate a reader page using an outdated sub-buffer order due to concurrent changes by ring_buffer_subbuf_order_set. This could cause the allocated memory's order to not match the expected value, potentially leading to memory inconsistencies. The vulnerability was fixed by modifying the allocation to use the bpage->order value, ensuring consistency and preventing the race.
Potential Impact
The vulnerability could cause memory allocation inconsistencies in the ring buffer reader page due to a race condition. However, the description notes that the user can re-allocate a new reader page and try again, indicating the impact is limited and does not lead to a severe failure or compromise. There are no known exploits in the wild.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to address this race condition by using the correct order value during allocation. Users should apply the official kernel update that includes this fix once available. Patch status is not explicitly confirmed in the input; therefore, check the vendor advisory for current remediation guidance.
In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()… (CVE-2026-89503)
Description
A race condition vulnerability in the Linux kernel's ring buffer subsystem was resolved. The issue involves a race between ring_buffer_alloc_read_page() and ring_buffer_subbuf_order_set, which can cause allocation of a reader page with an outdated or mismatched order. This mismatch can lead to inconsistencies in memory allocation for the ring buffer reader page. The fix ensures that the allocation uses the correct order value to prevent this race condition.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel contained a race condition in the ring buffer code where ring_buffer_alloc_read_page() could allocate a reader page using an outdated sub-buffer order due to concurrent changes by ring_buffer_subbuf_order_set. This could cause the allocated memory's order to not match the expected value, potentially leading to memory inconsistencies. The vulnerability was fixed by modifying the allocation to use the bpage->order value, ensuring consistency and preventing the race.
Potential Impact
The vulnerability could cause memory allocation inconsistencies in the ring buffer reader page due to a race condition. However, the description notes that the user can re-allocate a new reader page and try again, indicating the impact is limited and does not lead to a severe failure or compromise. There are no known exploits in the wild.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to address this race condition by using the correct order value during allocation. Users should apply the official kernel update that includes this fix once available. Patch status is not explicitly confirmed in the input; therefore, check the vendor advisory for current remediation guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-c9wm-w8pc-47gc
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-89503"]
Threat ID: 6aa4a01655bf5e2cf5a866ea
Added to database: 09/12/2026, 00:43:02 UTC
Last enriched: 09/12/2026, 01:12:26 UTC
Last updated: 09/12/2026, 01:33:27 UTC
Views: 3
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