tracing: Drain deferred trigger frees if kthread creation fails
Summary
| CVE | CVE-2026-31481 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-22 14:16:45 UTC |
| Updated | 2026-04-28 11:38:47 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: tracing: Drain deferred trigger frees if kthread creation fails Boot-time trigger registration can fail before the trigger-data cleanup kthread exists. Deferring those frees until late init is fine, but the post-boot fallback must still drain the deferred list if kthread creation never succeeds. Otherwise, boot-deferred nodes can accumulate on trigger_data_free_list, later frees fall back to synchronously freeing only the current object, and the older queued entries are leaked forever. To trigger this, add the following to the kernel command line: trace_event=sched_switch trace_trigger=sched_switch.traceon,sched_switch.traceon The second traceon trigger will fail and be freed. This triggers a NULL pointer dereference and crashes the kernel. Keep the deferred boot-time behavior, but when kthread creation fails, drain the whole queued list synchronously. Do the same in the late-init drain path so queued entries are not stranded there either. |
Risk And Classification
Primary CVSS: v3.1 5.5 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.000180000 probability, percentile 0.049860000 (date 2026-04-26)
Problem Types: CWE-476
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Linux | Linux Kernel | All | All | All | All |
| Operating System | Linux | Linux Kernel | 6.19 | - | All | All |
| Operating System | Linux | Linux Kernel | 7.0 | rc1 | All | All |
| Operating System | Linux | Linux Kernel | 7.0 | rc2 | All | All |
| Operating System | Linux | Linux Kernel | 7.0 | rc3 | All | All |
| Operating System | Linux | Linux Kernel | 7.0 | rc4 | All | All |
| Operating System | Linux | Linux Kernel | 7.0 | rc5 | All | All |
| Operating System | Linux | Linux Kernel | 7.0 | rc6 | All | All |
| Operating System | Linux | Linux Kernel | 7.0 | rc7 | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 61d445af0a7c70018111919e47beaaee15653f2f 771624b7884a83bb9f922ae64ee41a5f8b7576c9 git | Not specified |
| CNA | Linux | Linux | affected 61d445af0a7c70018111919e47beaaee15653f2f 250ab25391edeeab8462b68be42e4904506c409c git | Not specified |
| CNA | Linux | Linux | affected 6.19 | Not specified |
| CNA | Linux | Linux | unaffected 6.19 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.19.11 6.19.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/250ab25391edeeab8462b68be42e4904506c409c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/771624b7884a83bb9f922ae64ee41a5f8b7576c9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.