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Linux Kernel PowerVR GPU VM Map Operation Skips the vm_ctx Lock, Racing with Find Operations and Causing NULL Pointer Dereference

Last refreshed2026-09-29

Status: NEW  |  Advisory ID: CVE-2026-68260

Key Details

CVECVE-2026-68260
CVSS Score / Version7.8 (High) / CVSS v3.1
Updated2026-08-17
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS Proseattack vector is local; attack complexity is low; privileges required is low; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high.

What to Know

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

drm/imagination: acquire vm_ctx->lock before mapping memory to GPU VM

The drm gpuvm code doesn't protect find operation against map operation,

and the driver needs to ensure a map operation shouldn't happen when a

find operation is in progress.

In some cases a find operation will be in progress when doing map/unmap

operations, and the find operation will do a NULL pointer dereference.

An example of the stack trace of such NULL dereference is shown below:

```

Unable to handle kernel access to user memory without uaccess routines at

virtual address 0000000000000010

[<ffffffff01e989d4>] drm_gpuva_find+0x28/0x6c [drm_gpuvm]

[<ffffffff01ed3a40>] pvr_vm_unmap+0x34/0x68 [powervr]

[<ffffffff01ec69da>] pvr_ioctl_vm_unmap+0x2e/0x50 [powervr]

[<ffffffff8080ce0a>] drm_ioctl_kernel+0x8e/0xdc

[<ffffffff8080d016>] drm_ioctl+0x1be/0x3e0

[<ffffffff802bec3e>] __riscv_sys_ioctl+0xba/0xc4

[<ffffffff80d858b2>] do_trap_ecall_u+0x23e/0x3f4

[<ffffffff80d92288>] handle_exception+0x168/0x174

```

As all occurences of drm_gpuva_find*() are already guarded by

vm_ctx->lock, make pvr_vm_map() to acquire this lock to prevent

disturbing any find operation. This fixes the NULL deference problem in

drm_gpuva_find*(). (NVD)

References

SourceReference
NVDhttps://nvd.nist.gov/vuln/detail/CVE-2026-68260
CVEhttps://www.cve.org/CVERecord?id=CVE-2026-68260