# CVE-2024-41070: KVM: PPC: Book3S HV: Prevent UAF in kvm_spapr_tce_attach_iommu_group()

> A use-after-free vulnerability in the Linux kernel's KVM PPC module allows local attackers to potentially execute arbitrary code or escalate privileges.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 29 Jul 2024
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-47991, BELL-CVE-2024-41070, DEBIAN-CVE-2024-41070, GHSA-pc3q-4rr7-6vrq, UBUNTU-CVE-2024-41070

## What is CVE-2024-41070?

CVE-2024-41070 is a high-severity use after free vulnerability in Linux kernel, published on 29 Jul 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

KVM: PPC: Book3S HV: Prevent UAF in kvm_spapr_tce_attach_iommu_group()

Al reported a possible use-after-free (UAF) in kvm_spapr_tce_attach_iommu_group().

It looks up `stt` from tablefd, but then continues to use it after doing
fdput() on the returned fd. After the fdput() the tablefd is free to be
closed by another thread. The close calls kvm_spapr_tce_release() and
then release_spapr_tce_table() (via call_rcu()) which frees `stt`.

Although there are calls to rcu_read_lock() in
kvm_spapr_tce_attach_iommu_group() they are not sufficient to prevent
the UAF, because `stt` is used outside the locked regions.

With an artifcial delay after the fdput() and a userspace program which
triggers the race, KASAN detects the UAF:

  BUG: KASAN: slab-use-after-free in kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm]
  Read of size 4 at addr c000200027552c30 by task kvm-vfio/2505
  CPU: 54 PID: 2505 Comm: kvm-vfio Not tainted 6.10.0-rc3-next-20240612-dirty #1
  Hardware name: 8335-GTH POWER9 0x4e1202 opal:skiboot-v6.5.3-35-g1851b2a06 PowerNV
  Call Trace:
    dump_stack_lvl+0xb4/0x108 (unreliable)
    print_report+0x2b4/0x6ec
    kasan_report+0x118/0x2b0
    __asan_load4+0xb8/0xd0
    kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm]
    kvm_vfio_set_attr+0x524/0xac0 [kvm]
    kvm_device_ioctl+0x144/0x240 [kvm]
    sys_ioctl+0x62c/0x1810
    system_call_exception+0x190/0x440
    system_call_vectored_common+0x15c/0x2ec
  ...
  Freed by task 0:
   ...
   kfree+0xec/0x3e0
   release_spapr_tce_table+0xd4/0x11c [kvm]
   rcu_core+0x568/0x16a0
   handle_softirqs+0x23c/0x920
   do_softirq_own_stack+0x6c/0x90
   do_softirq_own_stack+0x58/0x90
   __irq_exit_rcu+0x218/0x2d0
   irq_exit+0x30/0x80
   arch_local_irq_restore+0x128/0x230
   arch_local_irq_enable+0x1c/0x30
   cpuidle_enter_state+0x134/0x5cc
   cpuidle_enter+0x6c/0xb0
   call_cpuidle+0x7c/0x100
   do_idle+0x394/0x410
   cpu_startup_entry+0x60/0x70
   start_secondary+0x3fc/0x410
   start_secondary_prolog+0x10/0x14

Fix it by delaying the fdput() until `stt` is no longer in use, which
is effectively the entire function. To keep the patch minimal add a call
to fdput() at each of the existing return paths. Future work can convert
the function to goto or __cleanup style cleanup.

With the fix in place the test case no longer triggers the UAF.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-41070?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-41070?

Apply the vendor's patch.

## Is CVE-2024-41070 being exploited?

There is no known exploitation of CVE-2024-41070 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-41070 and fix it if it is affected.

What it is: CVE-2024-41070 is a high-severity use after free vulnerability in Linux kernel, published on 29 Jul 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-41070 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-41070/ (Markdown: https://insights.sbomify.com/CVE-2024-41070/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-41070
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-41070
- OSV: https://osv.dev/vulnerability/CVE-2024-41070

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-41070/
Summaries are generated and may contain mistakes; the official description above is the record.