CVE-2023-52492: Debian Linux

Medium severity, CVSS 4.4. EPSS: 0.3% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: dmaengine: fix NULL pointer in channel unregistration function __dma_async_device_channel_register() can fail. In case of failure, chan->local is freed (with free_percpu()), and chan->local is nullified. When dma_async_device_unregister() is called (because of managed API or intentionally by DMA controller driver), channels are unconditionally unregistered, leading to this NULL pointer: [ 1.318693] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0 [...] [ 1.484499] Call trace: [ 1.486930] device_del+0x40/0x394 [ 1.490314] device_unregister+0x20/0x7c [ 1.494220] __dma_async_device_channel_unregister+0x68/0xc0 Look at dma_async_device_register() function error path, channel device unregistration is done only if chan->local is not NULL. Then add the same condition at the beginning of __dma_async_device_channel_unregister() function, to avoid NULL pointer issue whatever the API used to reach this function.

Affected products

• Debian Debian Linux: version 10.0 only
• Linux Linux Kernel: from 5.6, before 5.10.210 (fixed in 5.10.210); from 5.11, before 5.15.149 (fixed in 5.15.149); from 5.16, before 6.1.76 (fixed in 6.1.76); from 6.2, before 6.6.15 (fixed in 6.6.15); from 6.7, before 6.7.3 (fixed in 6.7.3)

Published 2024-03-11. Last modified 2026-06-17.