CVE-2022-50145: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-50145 is a NULL pointer dereference vulnerability in the Linux kernel's dmaengine: sf-pdma driver caused by a data race when multiple threads concurrently access a DMA channel. The flaw was published on June 18, 2025, and affects Linux kernel versions 5.5–5.10.136, 5.11–5.15.60, 5.16–5.18.17, and 5.19–5.19.1. It carries a CVSS v3.1 base score of 5.5 (Medium), exploitable locally with low privileges and no user interaction required (Feedly, Kernel Patches).

The root cause is a data race (CWE-476: NULL Pointer Dereference) in the sf-pdma DMA engine driver. When multiple threads call device_prep_dma_memcpy() on the same DMA channel simultaneously, each thread can overwrite the channel's descriptor pointer before the previous descriptor has been consumed, leading to use of a freed or substituted descriptor. This triggers a kernel NULL pointer dereference at virtual address 0x00000000000000a0 in vchan_find_desc(), called from sf_pdma_tx_status(). The fix ensures descriptors are only changed after use and are acquired from the vc->desc_issued queue, removing direct thread access to the channel descriptor (Feedly).

Successful exploitation causes a kernel NULL pointer dereference (Oops), system hang, or crash, resulting in a complete denial of service of the affected host. There is no confidentiality or integrity impact — the vulnerability is limited to availability. Because exploitation requires local access with low privileges, the blast radius is confined to the affected system and does not directly enable lateral movement or data exfiltration (Feedly).

There is no known public proof-of-concept exploit and no evidence of in-the-wild exploitation at this time. The EPSS score is approximately 0.018% (0.000180), indicating a very low probability of exploitation in the near term. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Exploitation requires local, low-privilege access and the ability to spawn multiple threads using a DMA channel concurrently (Feedly).

Update the Linux kernel to one of the following patched versions: 5.10.137 or later (for the 5.5–5.10 series), 5.15.61 or later (for the 5.11–5.15 series), 5.18.18 or later (for the 5.16–5.18 series), or 5.19.2 or later (for the 5.19 series). Patches are available via the stable kernel tree on git.kernel.org. As a temporary workaround where patching is not immediately possible, limit multi-threaded concurrent usage of DMA channels or avoid using the sf-pdma driver in multi-threaded workloads (Feedly, Kernel Patches).