CVE-2024-44949

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

parisc: fix a possible DMA corruption

ARCH_DMA_MINALIGN was defined as 16 - this is too small - it may be possible that two unrelated 16-byte allocations share a cache line. If one of these allocations is written using DMA and the other is written using cached write, the value that was written with DMA may be corrupted.

This commit changes ARCH_DMA_MINALIGN to be 128 on PA20 and 32 on PA1.1 - that's the largest possible cache line size.

As different parisc microarchitectures have different cache line size, we define arch_slab_minalign(), cache_line_size() and dma_get_cache_alignment() so that the kernel may tune slab cache parameters dynamically, based on the detected cache line size.

Moderate impact is assigned to this vulnerability because triggering memory corruption requires specific local hardware interaction and concurrent direct memory access alongside cached CPU writes. The flaw is confined to Linux kernel support for the PA-RISC architecture, which is not compiled or supported in Red Hat Enterprise Linux releases. Consequently, standard Red Hat enterprise environments do not run affected architecture builds and are not exposed under normal configurations.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.