sched/ext: Fix invalid task state transitions on class switch
Summary
| CVE | CVE-2025-39780 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2025-09-11 17:15:43 UTC |
| Updated | 2026-07-30 06:23:44 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: sched/ext: Fix invalid task state transitions on class switch When enabling a sched_ext scheduler, we may trigger invalid task state transitions, resulting in warnings like the following (which can be easily reproduced by running the hotplug selftest in a loop): sched_ext: Invalid task state transition 0 -> 3 for fish[770] WARNING: CPU: 18 PID: 787 at kernel/sched/ext.c:3862 scx_set_task_state+0x7c/0xc0 ... RIP: 0010:scx_set_task_state+0x7c/0xc0 ... Call Trace: <TASK> scx_enable_task+0x11f/0x2e0 switching_to_scx+0x24/0x110 scx_enable.isra.0+0xd14/0x13d0 bpf_struct_ops_link_create+0x136/0x1a0 __sys_bpf+0x1edd/0x2c30 __x64_sys_bpf+0x21/0x30 do_syscall_64+0xbb/0x370 entry_SYSCALL_64_after_hwframe+0x77/0x7f This happens because we skip initialization for tasks that are already dead (with their usage counter set to zero), but we don't exclude them during the scheduling class transition phase. Fix this by also skipping dead tasks during class swiching, preventing invalid task state transitions. |
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
Problem Types: NVD-CWE-noinfo
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 5.5 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
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 |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected a8532fac7b5d27b8d62008a89593dccb6f9786ef 786f6314604b34c3e7de5f733f4e08e35c448a50 git | Not specified |
| CNA | Linux | Linux | affected a8532fac7b5d27b8d62008a89593dccb6f9786ef 6a32cbe95029ebe21cc08349fd7ef2a3d32d2043 git | Not specified |
| CNA | Linux | Linux | affected a8532fac7b5d27b8d62008a89593dccb6f9786ef ddf7233fcab6c247379d0928d46cc316ee122229 git | Not specified |
| CNA | Linux | Linux | affected 6.12 | Not specified |
| CNA | Linux | Linux | unaffected 6.12 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.44 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.16.4 6.16.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.17 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/786f6314604b34c3e7de5f733f4e08e35c448a50 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/ddf7233fcab6c247379d0928d46cc316ee122229 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/6a32cbe95029ebe21cc08349fd7ef2a3d32d2043 | 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.