In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
drm\/xe: Guard page-fault worker with runtime PM check<\/p>\n
During VM teardown, the VM’s runtime PM reference is dropped
\nasynchronously, allowing the device to autosuspend while stale page
\nfaults belonging to the now-dead VM are still queued. When the
\npage-fault worker later tries to ack one of these, it calls into
\nguc_ct_send_locked() on an already-suspended device, tripping:<\/p>\n
\u00a0 Assertion `!xe_pm_runtime_suspended(xe)` failed!
\n\u00a0 WARNING at xe_device.c:1267 xe_device_assert_mem_access+0x11c\/0x140 [xe]<\/p>\n
A live VM\/exec queue always holds a PM reference while it has
\noutstanding work, so if the device is suspended at ack time, the
\nowning context is already gone and the fault is stale.<\/p>\n
Take a runtime PM reference across the entire pagefault
\nqueue worker to safely deliver acks for torn-down VMs.<\/p>\n
v3:
\n – Move PM ref to the generic xe_pagefault_queue_work using
\n guard(xe_pm_runtime)(xe) instead of tracking it in the GuC
\n backend(Matt Brost).<\/p>\n
v2:
\n – Hold PM ref across the entire batch (begin\/end) instead of per-ack.
\n This prevents the device from autosuspending mid-batch, which would
\n leave write_only acks written but the end flush skipped, and skip
\n counter++, desyncing the cadence check.(Himal)
\n – Add a comment explaining stale faults.(Himal)<\/p>\n
(cherry picked from commit fcc2431d2213dc4d04250c4f1ae87d9c3ae0d455)
\n[Rodrigo: Added xe_device struct for compatibility while cherry-picking]<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
drm\/xe: Guard page-fault worker with runtime PM check<\/p>\n
During VM teardown, the VM’s runtime PM reference is dropped
\nasynchronously,<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-39062","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/39062","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=39062"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=39062"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=39062"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}