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

ata: libata-scsi: bound the ATA passthru sense descriptor writes

When an ATA PASS-THROUGH command to an ATAPI device fails, the sense buffer holds the device's REQUEST SENSE reply, and ata_scsi_set_passthru_sense_fields() trusts its additional length byte, sb[7], when adding the ATA Status Return descriptor. A faulty or malicious device can use that to make the kernel read and write past the 96-byte buffer in three ways:

- scsi_sense_desc_find() is passed sb[7] + 8 as the buffer length, so its clamp against sb[7] does nothing and the walk runs off the end. - A type-9 descriptor found near the end is filled in unchecked. - A new descriptor at sb[8 + len] needs len + 22 bytes, not len + 14, so len 75..82 writes up to 8 bytes past the end.

Reproduced with KASAN under qemu, with the emulated ATAPI REQUEST SENSE reply patched:

BUG: KASAN: slab-out-of-bounds in scsi_sense_desc_find+0x1a5/0x210 BUG: KASAN: slab-out-of-bounds in ata_scsi_qc_complete+0x1a15/0x1a50

Both are gone with this patch, and a valid descriptor is still filled in.

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

ata: libata-scsi: bound the ATA passthru sense descriptor writes

When an ATA PASS-THROUGH command to an ATAPI device fails, the sense buffer holds the device's REQUEST SENSE reply, and ata_scsi_set_passthru_sense_fields() trusts its additional length byte, sb[7], when adding the ATA Status Return descriptor. A faulty or malicious device can use that to make the kernel read and write past the 96-byte buffer in three ways:

- scsi_sense_desc_find() is passed sb[7] + 8 as the buffer length, so its clamp against sb[7] does nothing and the walk runs off the end. - A type-9 descriptor found near the end is filled in unchecked. - A new descriptor at sb[8 + len] needs len + 22 bytes, not len + 14, so len 75..82 writes up to 8 bytes past the end.

Reproduced with KASAN under qemu, with the emulated ATAPI REQUEST SENSE reply patched:

BUG: KASAN: slab-out-of-bounds in scsi_sense_desc_find+0x1a5/0x210 BUG: KASAN: slab-out-of-bounds in ata_scsi_qc_complete+0x1a15/0x1a50

Both are gone with this patch, and a valid descriptor is still filled in.

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 155 more

In the Linux kernel, the following vulnerability has been resolved: ata: libata-scsi: bound the ATA passthru sense descriptor writes When an ATA PASS-THROUGH command to an ATAPI device fails, the sense buffer holds the device's REQUEST SENSE reply, and ata_scsi_set_passthru_sense_fields() trusts its additional length byte, sb[7], when adding the ATA Status Return descriptor. A faulty or malicious device can use that to make the kernel read and write past the 96-byte buffer in three ways: - scsi_sense_desc_find() is passed sb[7] + 8 as the buffer length, so its clamp against sb[7] does nothing and the walk runs off the end. - A type-9 descriptor found near the end is filled in unchecked. - A new descriptor at sb[8 + len] needs len + 22 bytes, not len + 14, so len 75..82 writes up to 8 bytes past the end. Reproduced with KASAN under qemu, with the emulated ATAPI REQUEST SENSE reply patched: BUG: KASAN: slab-out-of-bounds in scsi_sense_desc_find+0x1a5/0x210 BUG: KASAN: slab-out-of-bounds in ata_scsi_qc_complete+0x1a15/0x1a50 Both are gone with this patch, and a valid descriptor is still filled in.