In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
lib: test_hmm: evict device pages on file close to avoid use-after-free<\/p>\n
Patch series “Minor hmm_test fixes and cleanups”.<\/p>\n
Two bugfixes a cleanup for the HMM kernel selftests. These were mostly
\nreported by Zenghui Yu with special thanks to Lorenzo for analysing and
\npointing out the problems.<\/p>\n
This patch (of 3):<\/p>\n
When dmirror_fops_release() is called it frees the dmirror struct but
\ndoesn’t migrate device private pages back to system memory first. This
\nleaves those pages with a dangling zone_device_data pointer to the freed
\ndmirror.<\/p>\n
If a subsequent fault occurs on those pages (eg. during coredump) the
\ndmirror_devmem_fault() callback dereferences the stale pointer causing a
\nkernel panic. This was reported [1] when running mm\/ksft_hmm.sh on arm64,
\nwhere a test failure triggered SIGABRT and the resulting coredump walked
\nthe VMAs faulting in the stale device private pages.<\/p>\n
Fix this by calling dmirror_device_evict_chunk() for each devmem chunk in
\ndmirror_fops_release() to migrate all device private pages back to system
\nmemory before freeing the dmirror struct. The function is moved earlier
\nin the file to avoid a forward declaration.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
lib: test_hmm: evict device pages on file close to avoid use-after-free<\/p>\n
Patch series “Minor hmm_test fixes and cleanups”.<\/p>\n
Two bug<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-15989","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/15989","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=15989"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15989"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15989"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}