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CVE-2024-40976

drm/lima: mask irqs in timeout path before hard reset

Published
Last modified
published
Not listed in CISA KEV
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

Summary

In the Linux kernel, the following vulnerability has been resolved: drm/lima: mask irqs in timeout path before hard reset There is a race condition in which a rendering job might take just long enough to trigger the drm sched job timeout handler but also still complete before the hard reset is done by the timeout handler. This runs into race conditions not expected by the timeout handler. In some very specific cases it currently may result in a refcount imbalance on lima_pm_idle, with a stack dump such as: [10136.669170] WARNING: CPU: 0 PID: 0 at drivers/gpu/drm/lima/lima_devfreq.c:205 lima_devfreq_record_idle+0xa0/0xb0 ... [10136.669459] pc : lima_devfreq_record_idle+0xa0/0xb0 ... [10136.669628] Call trace: [10136.669634] lima_devfreq_record_idle+0xa0/0xb0 [10136.669646] lima_sched_pipe_task_done+0x5c/0xb0 [10136.669656] lima_gp_irq_handler+0xa8/0x120 [10136.669666] __handle_irq_event_percpu+0x48/0x160 [10136.669679] handle_irq_event+0x4c/0xc0 We can prevent that race condition entirely by masking the irqs at the beginning of the timeout handler, at which point we give up on waiting for that job entirely. The irqs will be enabled again at the next hard reset which is already done as a recovery by the timeout handler.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • Linux Linux

    Version range not reported

  • Linux Linux

    5.2

References 6

git.kernel.org