Linux vulnerability

What happened

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.

Affected versions

Linux: 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 through before d903d99ffd22b0180bd745a43f221c21bcdd8d7c (git); 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 through before 445204550f894ca325ac80a21e3df177ad073798 (git); 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 through before 4379610c79bd88ddbea10e7f6c21e16d4b338c6b (git); 6.17 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.