In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ksmbd: fix use-after-free in oplock break notification<\/p>\n
smb2_oplock_break_noti() reads opinfo->conn without any lock and
\ndereferences it after two allocations which may sleep. When the
\ndurable handle owning the oplock is disconnected, session_fd_check()
\nclears opinfo->conn and drops its conn reference under ci->m_lock, and
\nthe last ksmbd_conn_put() frees the connection. A break triggered by
\nanother connection that races with the teardown can then resurrect the
\nfreed connection: ksmbd_conn_get() is a plain atomic_inc, and the
\nqueued break work later dereferences the stale conn via
\nksmbd_conn_write(), a use-after-free reachable by any authenticated
\nclient holding a durable batch oplock.<\/p>\n
Thread the caller’s inode into the notification path instead of taking
\na new reference on it. Every caller of oplock_break() already holds a
\nlive ksmbd_file (or an explicit ksmbd_inode_lookup_lock() reference,
\nin the parent lease break paths) on the inode that owns the break
\ntarget’s oplock list, so ci cannot be freed during the call, and its
\nlock can be taken without dereferencing opinfo->o_fp, which a
\nconcurrent close may free. Select and pin the connection under
\nci->m_lock, the same lock session_fd_check() and
\nksmbd_reopen_durable_fd() use to update opinfo->conn, so a concurrent
\ndetach either loses the race to the clear or keeps the connection
\nalive until the notification work releases it. Transfer the reference
\nto the work item and release it on allocation failures.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ksmbd: fix use-after-free in oplock break notification<\/p>\n
smb2_oplock_break_noti() reads opinfo->conn without any lock and
\ndereferenc<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-21259","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/21259","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=21259"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21259"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21259"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}