CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
Low
In the Linux kernel, the following vulnerability has been resolved: scsi: storvsc: Fix swiotlb bounce buffer leak in confidential VM storvsc_queuecommand() maps the scatter/gather list using scsi_dma_map(), which in a confidential VM allocates swiotlb bounce buffers. If the I/O submission fails in storvsc_do_io(), the I/O is typically retried by higher level code, but the bounce buffer memory is never freed. The mostly like cause of I/O submission failure is a full VMBus channel ring buffer, which is not uncommon under high I/O loads. Eventually enough bounce buffer memory leaks that the confidential VM can’t do any I/O. The same problem can arise in a non-confidential VM with kernel boot parameter swiotlb=force. Fix this by doing scsi_dma_unmap() in the case of an I/O submission error, which frees the bounce buffer memory.