CVE-2026-31485

/// Technical description

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]

[...]

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/// 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