CVE-2021-47047

/// Technical description

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

spi: spi-zynqmp-gqspi: return -ENOMEM if dma_map_single fails

The spi controller supports 44-bit address space on AXI in DMA mode,

so set dma_addr_t width to 44-bit to avoid using a swiotlb mapping.

In addition, if dma_map_single fails, it should return immediately

instead of continuing doing the DMA operation which bases on invalid

address.

This fixes the following crash which occurs in reading a big block

from flash:

[ 123.633577] zynqmp-qspi ff0f0000.spi: swiotlb buffer is full (sz: 4194304 bytes), total 32768 (slots), used 0 (slots)

[ 123.644230] zynqmp-qspi ff0f0000.spi: ERR:rxdma:memory not mapped

[ 123.784625] Unable to handle kernel paging request at virtual address 00000000003fffc0

[ 123.792536] Mem abort info:

[ 123.795313] ESR = 0x96000145

[ 123.798351] EC = 0x25: DABT (current EL), IL = 32 bits

[ 123.803655] SET = 0, FnV = 0

[ 123.806693] EA = 0, S1PTW = 0

[ 123.809818] Data abort info:

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References