Linux Kernel CVE-2025-40172

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

accel/qaic: Treat remaining == 0 as error in find_and_map_user_pages()

Currently, if find_and_map_user_pages() takes a DMA xfer request from the user with a length field set to 0, or in a rare case, the host receives QAIC_TRANS_DMA_XFER_CONT from the device where resources->xferred_dma_size is equal to the requested transaction size, the function will return 0 before allocating an sgt or setting the fields of the dma_xfer struct. In that case, encode_addr_size_pairs() will try to access the sgt which will lead to a general protection fault.

Return an EINVAL in case the user provides a zero-sized ALP, or the device requests continuation after all of the bytes have been transferred.

The vulnerability is in the mainline Linux kernel's accel/qaic driver and is fixed across multiple stable branches, as indicated by the four kernel.org stable commit references (11f08c30a3e4, 1ab9733d14cc, 48b1d42286bf, 551f1dfbcb7f). No explicit affected version range or CPE string was provided in the input, so exact vulnerable kernel versions must be confirmed from each stable branch and from distribution advisories. Ubuntu is confirmed affected via USN-8125-1 (https://ubuntu.com/security/notices/USN-8125-1) and USN-8126-1 (https://ubuntu.com/security/notices/USN-8126-1). Only systems that load the qaic driver - i.e., hosts equipped with Qualcomm Cloud AI 100 accelerators - are practically exposed.