CVE-2025-21738ata: libata-sff: Ensure that we cannot write outside the allocated buffer

Official 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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/a8f8cf87059ed1905c2a5c72f8b39a4f57b11b4c
• https://git.kernel.org/stable/c/d5e6e3000309359eae2a17117aa6e3c44897bf6c
• https://git.kernel.org/stable/c/0dd5aade301a10f4b329fa7454fdcc2518741902
• https://git.kernel.org/stable/c/0a17a9944b8d89ef03946121241870ac53ddaf45
• https://git.kernel.org/stable/c/6e74e53b34b6dec5a50e1404e2680852ec6768d2
• https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
• https://cert-portal.siemens.com/productcert/html/ssa-784472.html