CVE-2022-50426

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

remoteproc: imx_dsp_rproc: Add mutex protection for workqueue

The workqueue may execute late even after remoteproc is stopped or stopping, some resources (rpmsg device and endpoint) have been released in rproc_stop_subdevices(), then rproc_vq_interrupt() accessing these resources will cause kennel dump.

Call trace: virtqueue_add_split+0x1ac/0x560 virtqueue_add_inbuf+0x4c/0x60 rpmsg_recv_done+0x15c/0x294 vring_interrupt+0x6c/0xa4 rproc_vq_interrupt+0x30/0x50 imx_dsp_rproc_vq_work+0x24/0x40 [imx_dsp_rproc] process_one_work+0x1d0/0x354 worker_thread+0x13c/0x470 kthread+0x154/0x160 ret_from_fork+0x10/0x20

Add mutex protection in imx_dsp_rproc_vq_work(), if the state is not running, then just skip calling rproc_vq_interrupt().

Also the flush workqueue operation can't be added in rproc stop for the same reason. The call sequence is

rproc_shutdown -> rproc_stop ->rproc_stop_subdevices ->rproc->ops->stop() ->imx_dsp_rproc_stop ->flush_work -> rproc_vq_interrupt

The resource needed by rproc_vq_interrupt has been released in rproc_stop_subdevices, so flush_work is not safe to be called in imx_dsp_rproc_stop.

This vulnerability requires elevated privileges to trigger (CAP_SYS_ADMIN) as it relies on the user being able to stop/restart the DSP or send messages that trigger the virtqueue handler via remoteproc.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.