# CVE-2025-40247: drm/msm: Fix pgtable prealloc error path

> A null pointer dereference in the Linux kernel's DRM MSM driver allows local attackers to cause a system crash.

- **Severity:** Not scored
- **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:** 4 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-40247, DEBIAN-CVE-2025-40247, GHSA-q5jm-7jm9-cpgj, ROOT-OS-DEBIAN-11-CVE-2025-40247, ROOT-OS-DEBIAN-12-CVE-2025-40247, ROOT-OS-DEBIAN-13-CVE-2025-40247, ROOT-OS-UBUNTU-2204-CVE-2025-40247, ROOT-OS-UBUNTU-2404-CVE-2025-40247, UBUNTU-CVE-2025-40247

## What is CVE-2025-40247?

CVE-2025-40247 is a vulnerability in Linux, published on 4 Dec 2025. 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:

drm/msm: Fix pgtable prealloc error path

The following splat was reported:

    Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
    Mem abort info:
      ESR = 0x0000000096000004
      EC = 0x25: DABT (current EL), IL = 32 bits
      SET = 0, FnV = 0
      EA = 0, S1PTW = 0
      FSC = 0x04: level 0 translation fault
    Data abort info:
      ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
      CM = 0, WnR = 0, TnD = 0, TagAccess = 0
      GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
    user pgtable: 4k pages, 48-bit VAs, pgdp=00000008d0fd8000
    [0000000000000010] pgd=0000000000000000, p4d=0000000000000000
    Internal error: Oops: 0000000096000004 [#1]  SMP
    CPU: 5 UID: 1000 PID: 149076 Comm: Xwayland Tainted: G S                  6.16.0-rc2-00809-g0b6974bb4134-dirty #367 PREEMPT
    Tainted: [S]=CPU_OUT_OF_SPEC
    Hardware name: Qualcomm Technologies, Inc. SM8650 HDK (DT)
    pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
    pc : build_detached_freelist+0x28/0x224
    lr : kmem_cache_free_bulk.part.0+0x38/0x244
    sp : ffff000a508c7a20
    x29: ffff000a508c7a20 x28: ffff000a508c7d50 x27: ffffc4e49d16f350
    x26: 0000000000000058 x25: 00000000fffffffc x24: 0000000000000000
    x23: ffff00098c4e1450 x22: 00000000fffffffc x21: 0000000000000000
    x20: ffff000a508c7af8 x19: 0000000000000002 x18: 00000000000003e8
    x17: ffff000809523850 x16: ffff000809523820 x15: 0000000000401640
    x14: ffff000809371140 x13: 0000000000000130 x12: ffff0008b5711e30
    x11: 00000000001058fa x10: 0000000000000a80 x9 : ffff000a508c7940
    x8 : ffff000809371ba0 x7 : 781fffe033087fff x6 : 0000000000000000
    x5 : ffff0008003cd000 x4 : 781fffe033083fff x3 : ffff000a508c7af8
    x2 : fffffdffc0000000 x1 : 0001000000000000 x0 : ffff0008001a6a00
    Call trace:
     build_detached_freelist+0x28/0x224 (P)
     kmem_cache_free_bulk.part.0+0x38/0x244
     kmem_cache_free_bulk+0x10/0x1c
     msm_iommu_pagetable_prealloc_cleanup+0x3c/0xd0
     msm_vma_job_free+0x30/0x240
     msm_ioctl_vm_bind+0x1d0/0x9a0
     drm_ioctl_kernel+0x84/0x104
     drm_ioctl+0x358/0x4d4
     __arm64_sys_ioctl+0x8c/0xe0
     invoke_syscall+0x44/0x100
     el0_svc_common.constprop.0+0x3c/0xe0
     do_el0_svc+0x18/0x20
     el0_svc+0x30/0x100
     el0t_64_sync_handler+0x104/0x130
     el0t_64_sync+0x170/0x174
    Code: aa0203f5 b26287e2 f2dfbfe2 aa0303f4 (f8737ab6)
    ---[ end trace 0000000000000000 ]---

Since msm_vma_job_free() is called directly from the ioctl, this looks
like an error path cleanup issue.  Which I think results from
prealloc_cleanup() called without a preceding successful
prealloc_allocate() call.  So handle that case better.

Patchwork: https://patchwork.freedesktop.org/patch/678677/

## Which versions are affected by CVE-2025-40247?


## How do I fix CVE-2025-40247?

Apply the vendor's patch.

## Is CVE-2025-40247 being exploited?

There is no known exploitation of CVE-2025-40247 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40247 and fix it if it is affected.

What it is: CVE-2025-40247 is a vulnerability in Linux, published on 4 Dec 2025. 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-2025-40247 in the wild and no public exploit code.

Affected product: Linux. 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-2025-40247/ (Markdown: https://insights.sbomify.com/CVE-2025-40247/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40247
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40247
- OSV: https://osv.dev/vulnerability/CVE-2025-40247

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40247/
Summaries are generated and may contain mistakes; the official description above is the record.