From 4379610c79bd88ddbea10e7f6c21e16d4b338c6b Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Tue, 14 Jul 2026 13:55:04 -0700 Subject: [PATCH] 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 Signed-off-by: Will Deacon --- drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c index ae9ee4ab6644..ad69641dce0f 100644 --- a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c +++ b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c @@ -56,6 +56,8 @@ #define VINTF_ENABLED BIT(0) #define TEGRA241_VINTF_SID_MATCH(s) (0x0040 + 0x4*(s)) +#define VINTF_SID_MATCH_VIRT_SID GENMASK(20, 1) +#define VINTF_SID_MATCH_ENABLE BIT(0) #define TEGRA241_VINTF_SID_REPLACE(s) (0x0080 + 0x4*(s)) #define TEGRA241_VINTF_LVCMDQ_ERR_MAP_64(m) \ @@ -1255,7 +1257,7 @@ static int tegra241_vintf_init_vsid(struct iommufd_vdevice *vdev) u64 virt_sid = vdev->virt_id; int sidx; - if (virt_sid > UINT_MAX) + if (virt_sid > FIELD_MAX(VINTF_SID_MATCH_VIRT_SID)) return -EINVAL; WARN_ON_ONCE(master->num_streams != 1); @@ -1267,7 +1269,9 @@ static int tegra241_vintf_init_vsid(struct iommufd_vdevice *vdev) return sidx; writel(stream->id, REG_VINTF(vintf, SID_REPLACE(sidx))); - writel(virt_sid << 1 | 0x1, REG_VINTF(vintf, SID_MATCH(sidx))); + writel(FIELD_PREP(VINTF_SID_MATCH_VIRT_SID, virt_sid) | + VINTF_SID_MATCH_ENABLE, + REG_VINTF(vintf, SID_MATCH(sidx))); dev_dbg(vintf->cmdqv->dev, "VINTF%u: allocated SID_REPLACE%d for pSID=%x, vSID=%x\n", vintf->idx, sidx, stream->id, (u32)virt_sid);