In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
drm\/drm_exec: fix up contended obj when num_objects is 0<\/p>\n
drm_exec_prepare_array() silently returns success without calling
\ndrm_exec_lock_contended() when num_objects is zero. This breaks the
\ninvariant upheld by drm_exec_lock_obj(), where every entry point into
\nthe locking sequence must first attempt to lock any previously
\ncontended object before proceeding.<\/p>\n
Drivers that chain multiple drm_exec_prepare_array() calls per
\ndrm_exec_until_all_locked() iteration (e.g. amdgpu’s userq signal\/wait
\nioctls, which prepare separate read and write BO arrays) can pass an
\nempty array for one of the two calls. If contention is hit while
\npreparing the non-empty array, exec->contended is set and the loop
\nretries; on retry, the empty-array call preceding it is a no-op that
\nnever clears exec->contended, so drm_exec_retry_on_contention()
\nimmediately jumps back to the top of the loop without ever reaching
\nthe call that would resolve the contention. This spins forever.<\/p>\n
Fix it by having drm_exec_prepare_array() call drm_exec_lock_contended()
\ndirectly when num_objects is zero, so a pending contended object dont
\nloop infinitely.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
drm\/drm_exec: fix up contended obj when num_objects is 0<\/p>\n
drm_exec_prepare_array() silently returns success without calling
\ndrm_exe<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-29056","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/29056","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=29056"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=29056"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=29056"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}