Bug 2532062 (CVE-2026-89450) - CVE-2026-89450 kernel: iommu/tegra241-cmdqv: Reject a vSID wider than the SID_MATCH field
Summary: CVE-2026-89450 kernel: iommu/tegra241-cmdqv: Reject a vSID wider than the SID...
Keywords:
Status: NEW
Alias: CVE-2026-89450
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-11 20:24 UTC by OSIDB Bzimport
Modified: 2026-09-14 19:04 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2026-09-11 20:24:36 UTC
In the Linux kernel, the following vulnerability has been resolved:

iommu/tegra241-cmdqv: Reject a vSID wider than the SID_MATCH field

tegra241_vintf_init_vsid() programs the guest-provided vSID into SID_MATCH,
whose VIRT_SID field spans bits [20:1] with bit 0 as the match-enable flag.
The HW therefore matches only a 20-bit Stream ID.

The bound check rejects only virt_sid > UINT_MAX, which admits a value far
wider than the field. The write "virt_sid << 1 | 0x1" then drops every bit
above 20: a virt_sid of 0x80000000 lands as SID_MATCH = 0x1, a valid match
on vSID 0, so the entry aliases the wrong Stream ID. Because vdev->virt_id
is guest-controlled, a VMM can trigger it.

Validate virt_sid against the field width with FIELD_MAX(), and program the
register with FIELD_PREP() so the value and the field stay consistent.


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