Description

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

iommu: Don't reserve 0-length IOVA region

When the bootloader/firmware doesn't setup the framebuffers, their
address and size are 0 in "iommu-addresses" property. If IOVA region is
reserved with 0 length, then it ends up corrupting the IOVA rbtree with
an entry which has pfn_hi < pfn_lo.
If we intend to use display driver in kernel without framebuffer then
it's causing the display IOMMU mappings to fail as entire valid IOVA
space is reserved when address and length are passed as 0.
An ideal solution would be firmware removing the "iommu-addresses"
property and corresponding "memory-region" if display is not present.
But the kernel should be able to handle this by checking for size of
IOVA region and skipping the IOVA reservation if size is 0. Also, add
a warning if firmware is requesting 0-length IOVA region reservation.

Classification

CVE ID: CVE-2023-52455

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.08% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/98b8a550da83cc392a14298c4b3eaaf0332ae6ad
https://git.kernel.org/stable/c/5e23e283910c9f30248732ae0770bcb0c9438abf
https://git.kernel.org/stable/c/bb57f6705960bebeb832142ce9abf43220c3eab1

Timeline