CVE-2025-71221

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1b38da264674d6a0fe26a63996b8f88b88c3da48 < 3f0e0e2d9e752570041e95fd04635e2580097819affected
LinuxLinux1b38da264674d6a0fe26a63996b8f88b88c3da48 < dfb5e05227745de43b7fd589721817a4337c970daffected
LinuxLinux1b38da264674d6a0fe26a63996b8f88b88c3da48 < eba0c75670c022cb1f948600db972524bcfe8166affected
LinuxLinux1b38da264674d6a0fe26a63996b8f88b88c3da48 < fc023b8fab057f0c910856ff36d3e12a30b7af4aaffected
LinuxLinux1b38da264674d6a0fe26a63996b8f88b88c3da48 < 9f665b3c3d9a168410251f27a5d019b7bf93185caffected
LinuxLinux1b38da264674d6a0fe26a63996b8f88b88c3da48 < a143545855bc2c6e1330f6f57ae375ac44af00a7affected
LinuxLinux3.16affected
LinuxLinux0 < 3.16unaffected
LinuxLinux5.15.209 <= 5.15.*unaffected
LinuxLinux6.1.167 <= 6.1.*unaffected
LinuxLinux6.6.130 <= 6.6.*unaffected
LinuxLinux6.12.78 <= 6.12.*unaffected
LinuxLinux6.18.10 <= 6.18.*unaffected
LinuxLinux6.19 <= *unaffected

Weaknesses

References