TOCTOU double copyin in illumos dld ioctl handling causes kernel heap corruption
Summary
| CVE | CVE-2026-15449 |
|---|---|
| State | PUBLISHED |
| Assigner | illumos |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-16 20:16:44 UTC |
| Updated | 2026-07-17 18:45:53 UTC |
| Description | A time-of-check to time-of-use (TOCTOU) flaw in the illumos data-link pseudo-driver (dld) affects handling of the DLDIOC_GETMACPROP and DLDIOC_SETMACPROP ioctls on /dev/dld. drv_ioc_prop_common() in usr/src/uts/common/io/dld/dld_drv.c copies the dld_ioc_macprop_t ioctl header in once to read its pr_valsize field, sizes and allocates a kernel heap buffer from that value, and then copies the full request in a second time from the same unprivileged user address. A concurrent thread can enlarge pr_valsize between the two copyins, so the second copyin and the subsequent property handling write beyond the end of the undersized allocation and corrupt the kernel heap. An unprivileged local user, including one confined to a non-global zone that owns a datalink, can trigger this to panic the system. The resulting kernel heap corruption may be usable for further compromise. |
Risk And Classification
Primary CVSS: v4.0 5.8 MEDIUM from 0ca53633-f0b5-4853-ba72-e0a2e62000d0
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.000840000 probability, percentile 0.003730000 (date 2026-07-20)
Problem Types: CWE-122 | CWE-367 | CWE-367 CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition | CWE-122 CWE-122 Heap-based Buffer Overflow
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 0ca53633-f0b5-4853-ba72-e0a2e62000d0 | Secondary | 5.8 | MEDIUM | CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 5.8 | MEDIUM | CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N |
CVSS v4.0 Breakdown
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Illumos | Illumos-gate | affected eae72b5b807baa9116e64502cbb278edf15f3146 6959feb5b430411a4809b06c53dcdb42fb525eac git | Not specified |
| CNA | OmniOS | OmniOS | affected any r151054 custom | Not specified |
| CNA | OmniOS | OmniOS | affected r151058 r151058j custom | Not specified |
| CNA | OmniOS | OmniOS | affected r151056 r151056aj custom | Not specified |
| CNA | OmniOS | OmniOS | affected r151054 r151054bj custom | Not specified |
| CNA | Triton Data Center | SmartOS | affected any 202060709 custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| illumos.org/issues/18020 | 0ca53633-f0b5-4853-ba72-e0a2e62000d0 | illumos.org | |
| illumos.topicbox.com/groups/developer/T923147fae854a738-M03c29e1be33dac2a5e3d9535/... | 0ca53633-f0b5-4853-ba72-e0a2e62000d0 | illumos.topicbox.com | |
| github.com/illumos/illumos-gate/commit/6959feb5b430411a4809b06c53dcdb42f... | 0ca53633-f0b5-4853-ba72-e0a2e62000d0 | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Nick Wilkens of Edgecast Cloud (en)
CNA: Dan McDonald (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-07-08T19:00:00.000Z | Disclosed |
Solutions
CNA: Update your illumos distribution to one that includes the fix for issue 18020.
Workarounds
CNA: No mitigation is available. The referenced notification includes a DTrace script that detects exploitation attempts.