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.

Fixes: 4dc0d12474f9 ("iommu/tegra241-cmdqv: Add user-space use support")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>

0 files changed, 0 insertions, 0 deletions