In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
iommu\/amd: Remove latent out-of-bounds access in IOMMU debugfs<\/p>\n
In iommu_mmio_write() and iommu_capability_write(), the variables
\ndbg_mmio_offset and dbg_cap_offset are declared as int. However, they
\nare populated using kstrtou32_from_user(). If a user provides a
\nsufficiently large value, it can become a negative integer.<\/p>\n
Prior to this patch, the AMD IOMMU debugfs implementation was already
\nprotected by different mechanisms.<\/p>\n
1. #define OFS_IN_SZ 8 ensures the user string OFS_IN_SZ)
\n return -EINVAL;<\/p>\n
2. Implicit type promotion in iommu_mmio_write(), dbg_mmio_offset is int
\n and iommu->mmio_phys_end is u64<\/p>\n
if (dbg_mmio_offset > iommu->mmio_phys_end – sizeof(u64))
\n return -EINVAL;<\/p>\n
3. The show handlers would currently catch the negative number and
\n refuse to perform the read.<\/p>\n
Replace kstrtou32_from_user() with kstrtos32_from_user() to parse the
\ninput, and check for negative values to explicitly prevent out-of-bounds
\nmemory accesses directly in iommu_mmio_write() and
\niommu_capability_write().<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
iommu\/amd: Remove latent out-of-bounds access in IOMMU debugfs<\/p>\n
In iommu_mmio_write() and iommu_capability_write(), the variables
\nd<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-15116","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/15116","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15116"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15116"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15116"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}