CVE-2025-21738

/// Technical description

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

ata: libata-sff: Ensure that we cannot write outside the allocated buffer

reveliofuzzing reported that a SCSI_IOCTL_SEND_COMMAND ioctl with out_len

set to 0xd42, SCSI command set to ATA_16 PASS-THROUGH, ATA command set to

ATA_NOP, and protocol set to ATA_PROT_PIO, can cause ata_pio_sector() to

write outside the allocated buffer, overwriting random memory.

While a ATA device is supposed to abort a ATA_NOP command, there does seem

to be a bug either in libata-sff or QEMU, where either this status is not

set, or the status is cleared before read by ata_sff_hsm_move().

Anyway, that is most likely a separate bug.

Looking at __atapi_pio_bytes(), it already has a safety check to ensure

that __atapi_pio_bytes() cannot write outside the allocated buffer.

Add a similar check to ata_pio_sector(), such that also ata_pio_sector()

cannot write outside the allocated buffer.

/// 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