In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
btrfs: zstd: fix lost wakeup when waiting for a workspace<\/p>\n
A writer can sleep forever in zstd_get_workspace() even though a workspace
\nis free. When zstd_alloc_workspace() fails, the task is queued on
\nzwsm->wait and schedules unconditionally, never re-testing the pool.
\nzstd_put_workspace() publishes the workspace and then calls cond_wake_up(),
\nwhich only wakes when a sleeper is already visible, so a workspace returned
\nbetween the failed allocation and prepare_to_wait() wakes nobody. The
\nwindow is wide: zstd_alloc_workspace() goes through kvmalloc() and may
\nenter reclaim.<\/p>\n
Only a max level workspace triggers the wakeup and one is deliberately kept
\nallocated as the fallback every waiter waits for, so once its wakeup is
\nlost the writer stays in TASK_UNINTERRUPTIBLE until some other task happens
\nto return one. Re-check the pool after prepare_to_wait() has published the
\nwaiter, and use the workspace if one turned up.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
btrfs: zstd: fix lost wakeup when waiting for a workspace<\/p>\n
A writer can sleep forever in zstd_get_workspace() even though a workspa<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-29234","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/29234","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=29234"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=29234"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=29234"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}