Bug 1220332 (CVE-2023-52455)

Summary:	VUL-0: CVE-2023-52455: kernel-source,kernel-source-azure,kernel-source-rt: iommu: IOVA rbtree corruption via zero-length IOVA region
Product:	[Novell Products] SUSE Security Incidents	Reporter:	SMASH SMASH <smash_bz>
Component:	Incidents	Assignee:	Kernel Bugs <kernel-bugs>
Status:	RESOLVED FIXED	QA Contact:	Security Team bot <security-team>
Severity:	Normal
Priority:	P5 - None	CC:	carlos.lopez
Version:	unspecified
Target Milestone:	---
Hardware:	Other
OS:	Other
URL:	https://smash.suse.de/issue/394968/
Whiteboard:	CVSSv3.1:SUSE:CVE-2023-52455:6.7:(AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H)
Found By:	Security Response Team	Services Priority:
Business Priority:		Blocker:	---
Marketing QA Status:	---	IT Deployment:	---

Description SMASH SMASH 2024-02-26 10:01:49 UTC

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.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-52455
https://git.kernel.org/stable/c/98b8a550da83cc392a14298c4b3eaaf0332ae6ad
https://git.kernel.org/stable/c/bb57f6705960bebeb832142ce9abf43220c3eab1
https://www.cve.org/CVERecord?id=CVE-2023-52455
https://git.kernel.org/stable/c/5e23e283910c9f30248732ae0770bcb0c9438abf
https://bugzilla.redhat.com/show_bug.cgi?id=2265793

Comment 1 Carlos López 2024-02-26 10:04:34 UTC

a5bf3cfce8cb ("iommu: Implement of_iommu_get_resv_regions()") only got into the SLE15-SP6 branch (plus stable and master), and we already have the fix there, so nothing to do. Closing.