CVE-2026-31485

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

spi: spi-fsl-lpspi: fix teardown order issue (UAF)

There is a teardown order issue in the driver. The SPI controller is

registered using devm_spi_register_controller(), which delays

unregistration of the SPI controller until after the fsl_lpspi_remove()

function returns.

As the fsl_lpspi_remove() function synchronously tears down the DMA

channels, a running SPI transfer triggers the following NULL pointer

dereference due to use after free:

| fsl_lpspi 42550000.spi: I/O Error in DMA RX

| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000

[...]

| Call trace:

| fsl_lpspi_dma_transfer+0x260/0x340 [spi_fsl_lpspi]

| fsl_lpspi_transfer_one+0x198/0x448 [spi_fsl_lpspi]

| spi_transfer_one_message+0x49c/0x7c8

| __spi_pump_transfer_message+0x120/0x420

| __spi_sync+0x2c4/0x520

| spi_sync+0x34/0x60

| spidev_message+0x20c/0x378 [spidev]

| spidev_ioctl+0x398/0x750 [spidev]

[...]

Switch from devm_spi_register_controller() to spi_register_controller() in

fsl_lpspi_probe() and add the corresponding spi_unregister_controller() in

fsl_lpspi_remove().