CVE-2023-53094: Linux Kernel

Medium severity, CVSS 4.7. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: tty: serial: fsl_lpuart: fix race on RX DMA shutdown From time to time DMA completion can come in the middle of DMA shutdown: <process ctx>: <IRQ>: lpuart32_shutdown() lpuart_dma_shutdown() del_timer_sync() lpuart_dma_rx_complete() lpuart_copy_rx_to_tty() mod_timer() lpuart_dma_rx_free() When the timer fires a bit later, sport->dma_rx_desc is NULL: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004 pc : lpuart_copy_rx_to_tty+0xcc/0x5bc lr : lpuart_timer_func+0x1c/0x2c Call trace: lpuart_copy_rx_to_tty lpuart_timer_func call_timer_fn __run_timers.part.0 run_timer_softirq __do_softirq __irq_exit_rcu irq_exit handle_domain_irq gic_handle_irq call_on_irq_stack do_interrupt_handler ... To fix this fold del_timer_sync() into lpuart_dma_rx_free() after dmaengine_terminate_sync() to make sure timer will not be re-started in lpuart_copy_rx_to_tty() <= lpuart_dma_rx_complete().

Affected products

• Linux Linux Kernel: from 3.18.9, before 3.19 (fixed in 3.19); from 3.19.1, before 5.10.177 (fixed in 5.10.177); from 5.11, before 5.15.105 (fixed in 5.15.105); from 5.16, before 6.1.23 (fixed in 6.1.23); from 6.2, before 6.2.8 (fixed in 6.2.8); version 6.3 only

Published 2025-05-02. Last modified 2026-08-04.