CVE-2025-71221 dmaengine: mmp_pdma: Fix race condition in mmp_pdma_residue()
A race condition in the Linux kernel MMP PDMA driver allows use-after-free, potentially leading to code execution or denial of service.
- 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-2025-71221?
CVE-2025-71221 is a high-severity vulnerability in Linux kernel, published on 14 Feb 2026. 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:
dmaengine: mmp_pdma: Fix race condition in mmp_pdma_residue()
Add proper locking in mmp_pdma_residue() to prevent use-after-free when accessing descriptor list and descriptor contents.
The race occurs when multiple threads call tx_status() while the tasklet on another CPU is freeing completed descriptors:
CPU 0 CPU 1 ----- ----- mmp_pdma_tx_status() mmp_pdma_residue() -> NO LOCK held list_for_each_entry(sw, ..) DMA interrupt dma_do_tasklet() -> spin_lock(&desc_lock) list_move(sw->node, ...) spin_unlock(&desc_lock) | dma_pool_free(sw) <- FREED! -> access sw->desc <- UAF!
This issue can be reproduced when running dmatest on the same channel with multiple threads (threads_per_chan > 1).
Fix by protecting the chain_running list iteration and descriptor access with the chan->desc_lock spinlock.
Weakness: CWE-362
Which versions are affected by CVE-2025-71221?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-71221?
Apply the vendor's patch.
Is CVE-2025-71221 being exploited?
There is no known exploitation of CVE-2025-71221 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-71221, DEBIAN-CVE-2025-71221, GHSA-959m-9w2w-7jxc, ROOT-OS-DEBIAN-11-CVE-2025-71221, ROOT-OS-DEBIAN-12-CVE-2025-71221, ROOT-OS-DEBIAN-13-CVE-2025-71221 and 3 more.