iommu/amd: Fix potential out-of-bounds read in iommu_mmio_show
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.2%
exploitation probability
0.2%top 95% of all CVEs
observed exploitation
nono source reports it
In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: Fix potential out-of-bounds read in iommu_mmio_show
In iommu_mmio_write(), it validates the user-provided offset with the
check: `iommu->dbg_mmio_offset > iommu->mmio_phys_end - 4`.
This assumes a 4-byte access. However, the corresponding
show handler, iommu_mmio_show(), uses readq() to perform an 8-byte
(64-bit) read.
If a user provides an offset equal to `mmio_phys_end - 4`, the check
passes, and will lead to a 4-byte out-of-bounds read.
Fix this by adjusting the boundary check to use sizeof(u64), which
corresponds to the size of the readq() operation.
Affected products
Linux · Linux