CVE-2022-48890

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> scsi: storvsc: Fix swiotlb bounce buffer leak in confidential VM<br /> <br /> storvsc_queuecommand() maps the scatter/gather list using scsi_dma_map(),<br /> which in a confidential VM allocates swiotlb bounce buffers. If the I/O<br /> submission fails in storvsc_do_io(), the I/O is typically retried by higher<br /> level code, but the bounce buffer memory is never freed. The mostly like<br /> cause of I/O submission failure is a full VMBus channel ring buffer, which<br /> is not uncommon under high I/O loads. Eventually enough bounce buffer<br /> memory leaks that the confidential VM can&amp;#39;t do any I/O. The same problem<br /> can arise in a non-confidential VM with kernel boot parameter<br /> swiotlb=force.<br /> <br /> Fix this by doing scsi_dma_unmap() in the case of an I/O submission<br /> error, which frees the bounce buffer memory.