CVE-2026-90317
bpf: Invalidate RCU pointers after final spin unlock
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Invalidate RCU pointers after final spin unlock In a sleepable BPF program, a spin lock can provide the only RCU protection for a kptr. The final bpf_spin_unlock() ends that protection, but the verifier leaves the pointer valid. Another CPU can then free the object before the pointer is used. A capability-limited runtime PoC triggered a task_struct use-after-free in __bpf_get_task_stack(). Record whether the program is in an RCU-protected context before releasing the lock. Invalidate RCU-protected pointers only when the unlock leaves the final such context. This preserves valid pointers in non-sleepable programs and inside an explicit RCU read-side section.
INFO
Published Date :
Sept. 17, 2026, 5:17 p.m.
Last Modified :
Sept. 18, 2026, 6:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to include the BPF RCU fix.
- Record RCU protection context before releasing spin locks.
- Invalidate RCU pointers when exiting the final protection context.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-90317.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/180c7000712db77063b3a26f4c97e7dd9038f449 | |
| https://git.kernel.org/stable/c/7ae71629357d0a6d0bdadb929c7b296d5b7e61c2 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-90317 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-90317
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-90317 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-90317 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 18, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 17, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: bpf: Invalidate RCU pointers after final spin unlock In a sleepable BPF program, a spin lock can provide the only RCU protection for a kptr. The final bpf_spin_unlock() ends that protection, but the verifier leaves the pointer valid. Another CPU can then free the object before the pointer is used. A capability-limited runtime PoC triggered a task_struct use-after-free in __bpf_get_task_stack(). Record whether the program is in an RCU-protected context before releasing the lock. Invalidate RCU-protected pointers only when the unlock leaves the final such context. This preserves valid pointers in non-sleepable programs and inside an explicit RCU read-side section. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/90xxx/CVE-2026-90317.json">CVE-2026-90317</a> Added Reference https://git.kernel.org/stable/c/180c7000712db77063b3a26f4c97e7dd9038f449 Added Reference https://git.kernel.org/stable/c/7ae71629357d0a6d0bdadb929c7b296d5b7e61c2