drm/imagination: Fix reference and vm_bo handling in remap()

Summary

In the Linux kernel, the following vulnerability has been resolved: drm/imagination: Fix reference and vm_bo handling in remap() When a map overlaps part of an existing mapping, pvr_vm_gpuva_remap() splits the mapping into prev/next parts covering what the request did not take, instead of creating something new. It gets two things wrong. • A GEM reference is taken for each part but it's never needed and never dropped, so it leaks one reference per split (remap-next-in-2m in tests/imagination/pvr_vm_map.c): CRITICAL: 33558528 bytes of shmem still held after close • The parts still belong to the original object being split, but pvr_vm_gpuva_remap() links them to ctx->gpuvm_bo, the new object's vm_bo: prev_va --obj--> BO_A BO_B <--obj-- vm_bo (ctx->gpuvm_bo) \_________link_________/ (mismatch: BO_A != BO_B) drm_gpuva_link() catches the mismatch: WARNING: drivers/gpu/drm/drm_gpuvm.c:2108 at drm_gpuva_link+0x2ec/0x310 drm_WARN_ON(obj != vm_bo->obj) Call trace: drm_gpuva_link pvr_vm_gpuva_remap __drm_gpuvm_sm_map pvr_vm_map pvr_ioctl_vm_map Link them to op->remap.unmap->va->vm_bo instead. The locking of the GPUVA lists of the other objects touched by a split is not addressed here; it is handled by switching the GPUVM to immediate mode.

Timeline

1. Oct 23, 2026, 12:19 PM UTCCVE published
2. Oct 23, 2026, 12:20 PM UTCFirst seen by cve.now

Affected versions

• Linux Linux

  From ff5f643de0bf27874c4033cd57a0bd034b5c7d11 · fixed in 521cf8403a185a9d5790fe324bb43ba7ea85f51c; From ff5f643de0bf27874c4033cd57a0bd034b5c7d11 · fixed in 9caa2eca5cc8372517ff36a83f321d4326abae93; From ff5f643de0bf27874c4033cd57a0bd034b5c7d11 · fixed in 784356aa88b82035d70e9faeded49b70cddeb29e; From ff5f643de0bf27874c4033cd57a0bd034b5c7d11 · fixed in 196d4d10c1b33ae176685ff42a9994a5952b1d0f

• Linux Linux

  6.8

• KernelLinux

  From 6.8.0 · fixed in 6.12.113; From 6.13.0 · fixed in 6.18.57; From 6.19.0 · fixed in 7.2.11

References 4