CVE-2025-40172 accel/qaic: Treat remaining == 0 as error in find_and_map_user_pages()
A local attacker can trigger a general protection fault and crash the system by sending a zero-length DMA transfer request to the QAIC accelerator driver.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-40172?
CVE-2025-40172 is a high-severity vulnerability in Linux, published on 12 Nov 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2025-40172?
How do I fix CVE-2025-40172?
Apply the vendor's patch.
Is CVE-2025-40172 being exploited?
There is no known exploitation of CVE-2025-40172 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-40172, DEBIAN-CVE-2025-40172, GHSA-q638-pmrf-wwcc, ROOT-OS-DEBIAN-13-CVE-2025-40172, ROOT-OS-UBUNTU-2404-CVE-2025-40172, UBUNTU-CVE-2025-40172.