CVE-2026-89992 PUBLISHED

cpuidle: dt_idle_genpd: kfree() the original name allocation

Assigner: Linux
Reserved: 11.09.2026 Published: 16.09.2026 Updated: 16.09.2026

In the Linux kernel, the following vulnerability has been resolved:

cpuidle: dt_idle_genpd: kfree() the original name allocation

dt_idle_pd_alloc() kasprintf()s the full node path, then points pd->name at kbasename() of that string. dt_idle_pd_free() kfree()s pd->name, which is no longer the start of the allocation.

Copy the basename instead.

Metrics

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 8.4

AV:L - The invalid free is reached only from local PSCI and RISC-V SBI CPU idle genpd bring-up (psci_cpuidle_domain_probe and sbi_genpd_probe calling dt_idle_pd_alloc/dt_idle_pd_free) on ARM phones, automotive, and RISC-V boards; no network, Bluetooth, or USB receive path calls this code. AC:L - After dt_idle_pd_alloc() succeeds, pd->name is an interior kbasename() pointer into the kasprintf() buffer; any later psci_pd_init/sbi_pd_init unwind (ENOMEM from genpd_alloc_data or pd_provider, or of_genpd_add_provider_simple failure) deterministically kfree()s that pointer, with no race or layout lottery. PR:N - Both callers are builtin initcalls (core_initcall/arch_initcall) whose platform probe runs automatically on hierarchical CPU idle DT with no capability or credential check, so a Linux account is not required to reach the vulnerable unwind. UI:N - Probe and error unwind run during kernel initialization and deferred-probe retries; no victim needs to mount a filesystem, open a device, or load a module. S:U - The interior-pointer kfree corrupts host kernel SLUB state within the same security authority and does not escape a VM, bypass IOMMU, or cross another sandbox boundary. C:H - kfree() of an interior kasprintf() pointer is an invalid free that corrupts slab metadata and overlapping objects; that memory-corruption primitive can be groomed into arbitrary kernel memory disclosure. I:H - SLUB treats the misaligned interior address as an object and corrupts the freelist; heap grooming can produce overlapping allocations and write primitives enabling control-flow hijack, matching this CNA's invalid-free scoring. A:H - Debug and KASAN builds oops on the invalid free, and without them the corrupted slab commonly panics during CPU idle genpd bring-up, so availability impact is a kernel crash.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 9d976d6721dfb525b81ce981e1363c70c0975aab to 1312ae33b91430ec99e69cd3d47f0e50a4ebf54b (excl.)
  • affected from 9d976d6721dfb525b81ce981e1363c70c0975aab to a38caa9ed0d5c61c17d88393b14b292199289c1f (excl.)
  • affected from 9d976d6721dfb525b81ce981e1363c70c0975aab to 09d002c8fb0261d35ce9d8a705de5db034ee90b8 (excl.)
  • affected from 9d976d6721dfb525b81ce981e1363c70c0975aab to b519dfce1998c323e54a56f911cf708d9ba0e076 (excl.)
  • affected from 9d976d6721dfb525b81ce981e1363c70c0975aab to 3394c7ba23336bdb7ece29127130fd01731d42d8 (excl.)
  • affected from 9d976d6721dfb525b81ce981e1363c70c0975aab to 2b0ac85512b7f67479127b2713254490662eb13d (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 5.18 is affected
  • unaffected from 0 to 5.18 (excl.)
  • unaffected from 6.1.188 to 6.1.* (incl.)
  • unaffected from 6.6.157 to 6.6.* (incl.)
  • unaffected from 6.12.110 to 6.12.* (incl.)
  • unaffected from 6.18.51 to 6.18.* (incl.)
  • unaffected from 7.2.5 to 7.2.* (incl.)
  • unaffected from 7.3-rc2 to * (incl.)

References