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