CVE-2023-53094

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinux4a8588a1cf867333187d9ff071e6fbdab587d194 < 19a98d56dfedafb25652bdb9cd48a4e73ceba702affected
LinuxLinux4a8588a1cf867333187d9ff071e6fbdab587d194 < 90530e7214c8a04dcdde57502d93fa96af288c38affected
LinuxLinux4a8588a1cf867333187d9ff071e6fbdab587d194 < 954fc9931f0aabf272b5674cf468affdd88d3a36affected
LinuxLinux4a8588a1cf867333187d9ff071e6fbdab587d194 < 2a36b444cace9580380467fd1183bb5e85bcc80aaffected
LinuxLinux4a8588a1cf867333187d9ff071e6fbdab587d194 < 1be6f2b15f902c02e055ae0b419ca789200473c9affected
LinuxLinux5716a781032693d0f812ed06528d98195e9df028affected
LinuxLinux0d5cb6e8b4b62d8efd1a470615894276341d6db9affected
LinuxLinux3.18.9 < 3.19affected
LinuxLinux3.19.1 < 3.20affected
LinuxLinux4.0affected
LinuxLinux0 < 4.0unaffected
LinuxLinux5.10.177 <= 5.10.*unaffected
LinuxLinux5.15.105 <= 5.15.*unaffected
LinuxLinux6.1.23 <= 6.1.*unaffected
LinuxLinux6.2.8 <= 6.2.*unaffected
LinuxLinux6.3 <= *unaffected

Weaknesses

References