io_uring/bpf-ops: reject re-registration of an already-bound ops
Summary
| CVE | CVE-2026-72112 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-15 06:21:25 UTC |
| Updated | 2026-08-17 06:18:10 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: io_uring/bpf-ops: reject re-registration of an already-bound ops io_install_bpf() only rejects a second registration on the ctx side (ctx->bpf_ops) and sets the per-map back-pointer ops->priv unconditionally. The struct_ops link path never advances a map past BPF_STRUCT_OPS_STATE_READY, so the same io_uring_bpf_ops map can be registered more than once, and bpf_io_reg() re-resolves the target ring via fget(ops->ring_fd) on every call. A caller can therefore point the same ring_fd at a different io_ring_ctx between two BPF_LINK_CREATE calls. The second registration passes the ctx->bpf_ops check (the new ctx has none) and overwrites ops->priv, orphaning the first ctx. Teardown (io_eject_bpf()/bpf_io_unreg()) only reaches a ctx through ops->priv, so the orphaned ctx is never torn down: its ctx->loop_step keeps pointing into the struct_ops trampoline, which is freed once the map is gone. A later io_uring_enter() on the orphaned ring then calls the dangling ctx->loop_step from io_run_loop() -- a use-after-free of freed executable memory, reachable by a task with CAP_BPF + CAP_PERFMON. Reject registration when ops->priv is already set, as hid_bpf_reg() does for its struct_ops. |
Risk And Classification
Primary CVSS: v3.1 7.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.001540000 probability, percentile 0.050520000 (date 2026-08-17)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 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
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 98f37634b12b17ad5c56db8fb63cf9d7dc55d74c 0639ea767fe04c288a8d6cb826100fe3d95d4936 git | Not specified |
| CNA | Linux | Linux | affected 98f37634b12b17ad5c56db8fb63cf9d7dc55d74c 3afc64c61ce906a04f073ca350b46de10e8302f9 git | Not specified |
| CNA | Linux | Linux | affected 7.1 | Not specified |
| CNA | Linux | Linux | unaffected 7.1 semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.5 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/3afc64c61ce906a04f073ca350b46de10e8302f9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/0639ea767fe04c288a8d6cb826100fe3d95d4936 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| 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.