In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
PCI\/sysfs: Add lockdown checks to legacy I\/O and memory handlers<\/p>\n
Currently, the legacy I\/O and memory sysfs handlers do not check
\nsecurity_locked_down(LOCKDOWN_PCI_ACCESS), leaving the legacy_io and
\nlegacy_mem files unprotected when the kernel is locked down.<\/p>\n
Commit eb627e17727e (“PCI: Lock down BAR access when the kernel is locked
\ndown”) added the check to pci_write_config(), pci_mmap_resource(), and
\npci_write_resource_io() to prevent userspace from programming DMA-capable
\nhardware that could be used to modify kernel code, but did not cover the
\nlegacy handlers.<\/p>\n
As a result, root can still write arbitrary I\/O ports and map the legacy
\nI\/O and memory spaces while the kernel is locked down, which is the same
\ncapability the lockdown is meant to remove.<\/p>\n
Add the same check to pci_write_legacy_io(), pci_mmap_legacy_mem(), and
\npci_mmap_legacy_io().<\/p>\n
These generic handlers cover both architectures that define HAVE_PCI_LEGACY
\n(such as Alpha and PowerPC).<\/p>\n
[bhelgaas: add Link]<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
PCI\/sysfs: Add lockdown checks to legacy I\/O and memory handlers<\/p>\n
Currently, the legacy I\/O and memory sysfs handlers do not check<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-25724","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/25724","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=25724"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=25724"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=25724"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}