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

drm/vc4: drain the hangcheck timer and works on V3D unbind

Nothing stops the hangcheck timer that submitted jobs arm, or the job_done_work that the render-done interrupt queues, at teardown: vc4_irq_disable() cancels only overflow_mem_work, and vc4_gem_destroy() runs from the drm-managed release, after vc4_v3d_unbind() has already uninstalled the V3D interrupt and cleared vc4->v3d. A timer still armed by then reads V3D registers through the NULL vc4->v3d pointer, and the late callbacks run on the vc4_dev embedding them after it has been freed.

Drain them in vc4_v3d_unbind(): shut the timer down and cancel reset_work before the interrupt is taken down, because its vc4_irq_reset() re-enables it, then flush job_done_work so that completions queued at teardown still release their jobs.

This issue was found by an in-house static analysis tool.

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

drm/vc4: drain the hangcheck timer and works on V3D unbind

Nothing stops the hangcheck timer that submitted jobs arm, or the job_done_work that the render-done interrupt queues, at teardown: vc4_irq_disable() cancels only overflow_mem_work, and vc4_gem_destroy() runs from the drm-managed release, after vc4_v3d_unbind() has already uninstalled the V3D interrupt and cleared vc4->v3d. A timer still armed by then reads V3D registers through the NULL vc4->v3d pointer, and the late callbacks run on the vc4_dev embedding them after it has been freed.

Drain them in vc4_v3d_unbind(): shut the timer down and cancel reset_work before the interrupt is taken down, because its vc4_irq_reset() re-enables it, then flush job_done_work so that completions queued at teardown still release their jobs.

This issue was found by an in-house static analysis tool.

Affected: Ubuntu:Pro:14.04:LTS: linux-azure, Ubuntu:Pro:16.04:LTS: linux-aws-hwe, Ubuntu:Pro:16.04:LTS: linux-azure, Ubuntu:Pro:16.04:LTS: linux-gcp, Ubuntu:Pro:16.04:LTS: linux-hwe, Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:Pro:16.04:LTS: linux-oracle, Ubuntu:Pro:18.04:LTS: linux, Ubuntu:Pro:18.04:LTS: linux-aws, Ubuntu:18.04:LTS: linux-aws-5.0 and 249 more

In the Linux kernel, the following vulnerability has been resolved: drm/vc4: drain the hangcheck timer and works on V3D unbind Nothing stops the hangcheck timer that submitted jobs arm, or the job_done_work that the render-done interrupt queues, at teardown: vc4_irq_disable() cancels only overflow_mem_work, and vc4_gem_destroy() runs from the drm-managed release, after vc4_v3d_unbind() has already uninstalled the V3D interrupt and cleared vc4->v3d. A timer still armed by then reads V3D registers through the NULL vc4->v3d pointer, and the late callbacks run on the vc4_dev embedding them after it has been freed. Drain them in vc4_v3d_unbind(): shut the timer down and cancel reset_work before the interrupt is taken down, because its vc4_irq_reset() re-enables it, then flush job_done_work so that completions queued at teardown still release their jobs. This issue was found by an in-house static analysis tool.