CVE-2026-89450high

CVE-2026-89450: high-severity vulnerability in Linux

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

Published · Updated

21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 8.8epss 0.2%
exploitation probability
0.2%top 94% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Affected products
Linux · Linux