CVE-2026-90008

/// Technical description

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

scsi: megaraid_sas: Limit NVMe request size to the PRP chain frame

megasas_make_prp_nvme() builds a command's PRP list in cmd->sg_frame, a

DMA pool buffer of instance->max_chain_frame_sz bytes, spending one

entry per NVMe page of the transfer plus one per page of the buffer for

the chain pointer. The loop runs until the transfer is described and

never checks the buffer bound.

max_hw_sectors comes straight from the MDTS the firmware reports for the

drive. On drives with a large MDTS the only thing keeping the list

inside the buffer was the block layer default of 1280 KiB, which needs

320 entries, which fit into a 4 KiB frame as that holds 512. But since

commit 9b8b84879d4a ("block: Increase BLK_DEF_MAX_SECTORS_CAP") that

default is 4 MiB, and such a transfer needs 1025 entries, so the list

runs a full page past the end of the frame:

sd 1:0:1:0: [sdb] tag#630 page boundary ptr_sgl: 0x00000000ba62d13f

BUG: unable

/// 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