In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
swiotlb: use the adjusted address for the highmem page lookup<\/p>\n
swiotlb_bounce() reads the page frame number from the slot’s recorded
\norig_addr, then advances orig_addr by tlb_offset to reach the address
\nthe caller asked about. The highmem branch mixes the two: the offset
\nwithin the page comes from the adjusted address, the page from the value
\nbefore it.<\/p>\n
Once the adjustment crosses a page boundary the pair no longer describes
\none location, and the whole copy lands one page below the intended one
\nfor a positive tlb_offset, one above for a negative one. DMA_FROM_DEVICE
\nwrites the device data over the wrong page and leaves the intended one
\nstale, DMA_TO_DEVICE feeds the device from a page the mapping may not
\ncover. Partial syncs through dma_sync_single_range_for_*() are what make
\ntlb_offset non-zero.<\/p>\n
The branch test is picked the same way, so a slot recorded in lowmem can
\nbe adjusted into highmem and the lowmem path then hands a highmem
\naddress to phys_to_virt().<\/p>\n
Take both from orig_addr once it is final and keep pfn in the branch
\nthat uses it. PhysHighMem() asks the question straight from the address,
\nas dma-debug already does.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
swiotlb: use the adjusted address for the highmem page lookup<\/p>\n
swiotlb_bounce() reads the page frame number from the slot’s recorde<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-33323","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/33323","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=33323"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=33323"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=33323"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}