CVE-2026-89450EPSS p6.1%
CVE-2026-89450CVE-2026-89450
Description
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.
Scoring
| CVSS | 8.8 () |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| EPSS | 0.17% probability of exploitation · percentile 6.1% · 2026-10-05T12:00:23Z |
| Last modified | 2026-09-13 |