Linux Kernel CVE-2025-68746

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

spi: tegra210-quad: Fix timeout handling

When the CPU that the QSPI interrupt handler runs on (typically CPU 0) is excessively busy, it can lead to rare cases of the IRQ thread not running before the transfer timeout is reached.

While handling the timeouts, any pending transfers are cleaned up and the message that they correspond to is marked as failed, which leaves the curr_xfer field pointing at stale memory.

To avoid this, clear curr_xfer to NULL upon timeout and check for this condition when the IRQ thread is finally run.

While at it, also make sure to clear interrupts on failure so that new interrupts can be run.

A better, more involved, fix would move the interrupt clearing into a hard IRQ handler. Ideally we would also want to signal that the IRQ thread no longer needs to be run after the timeout is hit to avoid the extra check for a valid transfer.

The Linux kernel, specifically the Tegra210 Quad SPI controller driver (spi-tegra210-quad) used on NVIDIA Tegra210-class SoCs, is affected on all versions containing the flawed timeout handling prior to the fix. No CPE strings were provided in the input and exact vulnerable version ranges were not enumerated by NVD; the affected/fixed boundaries can be derived from the seven stable-tree commits referenced (e.g., https://git.kernel.org/stable/c/bb0c58be84f907285af45657c1d4847b960a12bf and the parallel backports 01bbf25c..., 551060ef..., 83309dd5..., 88db8bb7..., b4e002d8..., c934e402...), which indicates backporting across multiple stable branches. Only systems that build and use the tegra210-quad SPI driver (NVIDIA Tegra hardware such as Jetson platforms) are exposed.