CVE-2022-50375

/// Technical description

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

tty: serial: fsl_lpuart: disable dma rx/tx use flags in lpuart_dma_shutdown

lpuart_dma_shutdown tears down lpuart dma, but lpuart_flush_buffer can

still occur which in turn tries to access dma apis if lpuart_dma_tx_use

flag is true. At this point since dma is torn down, these dma apis can

abort. Set lpuart_dma_tx_use and the corresponding rx flag

lpuart_dma_rx_use to false in lpuart_dma_shutdown so that dmas are not

accessed after they are relinquished.

Otherwise, when try to kill btattach, kernel may panic. This patch may

fix this issue.

root@imx8ulpevk:~# btattach -B /dev/ttyLP2 -S 115200

^C[ 90.182296] Internal error: synchronous external abort: 96000210 [#1] PREEMPT SMP

[ 90.189806] Modules linked in: moal(O) mlan(O)

[ 90.194258] CPU: 0 PID: 503 Comm: btattach Tainted: G O 5.15.32-06136-g34eecdf2f9e4 #37

[ 90.203554] Hardware name: NXP i.MX8ULP 9X9 EVK (DT)

[ 90.208513] pstate: 600000c5

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References