NULL Pointer Dereference Affecting kernel-default-base package, versions <5.14.21-150500.55.113.1.150500.6.53.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.03% (6th percentile)

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  • Snyk IDSNYK-SLES155-KERNELDEFAULTBASE-10729252
  • published12 Jul 2025
  • disclosed10 Jul 2025

Introduced: 10 Jul 2025

CVE-2022-50145  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade SLES:15.5 kernel-default-base to version 5.14.21-150500.55.113.1.150500.6.53.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-default-base package and not the kernel-default-base package as distributed by SLES. See How to fix? for SLES:15.5 relevant fixed versions and status.

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

dmaengine: sf-pdma: Add multithread support for a DMA channel

When we get a DMA channel and try to use it in multiple threads it will cause oops and hanging the system.

% echo 64 > /sys/module/dmatest/parameters/threads_per_chan % echo 10000 > /sys/module/dmatest/parameters/iterations % echo 1 > /sys/module/dmatest/parameters/run [ 89.480664] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a0 [ 89.488725] Oops [#1] [ 89.494708] CPU: 2 PID: 1008 Comm: dma0chan0-copy0 Not tainted 5.17.0-rc5 [ 89.509385] epc : vchan_find_desc+0x32/0x46 [ 89.513553] ra : sf_pdma_tx_status+0xca/0xd6

This happens because of data race. Each thread rewrite channels's descriptor as soon as device_prep_dma_memcpy() is called. It leads to the situation when the driver thinks that it uses right descriptor that actually is freed or substituted for other one.

With current fixes a descriptor changes its value only when it has been used. A new descriptor is acquired from vc->desc_issued queue that is already filled with descriptors that are ready to be sent. Threads have no direct access to DMA channel descriptor. Now it is just possible to queue a descriptor for further processing.

CVSS Base Scores

version 3.1