In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
mptcp: pm: fix memory leak from alloc-during-teardown race<\/p>\n
mptcp_pm_destroy() empties msk->pm.anno_list and
\nmsk->pm.userspace_pm_local_addr_list under msk->pm.lock during socket
\nteardown, dropping the lock between the two.<\/p>\n
A concurrent userspace PM genl ANNOUNCE on the same msk holds a sock
\nreference via mptcp_token_get_sock() and, in
\nmptcp_pm_nl_announce_doit(), calls
\nmptcp_userspace_pm_append_new_local_addr() and
\nmptcp_pm_announced_alloc(). Both take msk->pm.lock briefly to add to
\ntheir respective lists. Because the genl handler holds a sock reference,
\nmptcp_pm_destroy() may run on the same msk via mptcp_disconnect(), which
\ninvokes mptcp_destroy_common() without dropping the sock refcount,
\nbefore the handler completes.<\/p>\n
If the lock acquisitions interleave such that mptcp_pm_destroy() empties
\na list first, the later alloc adds its entry to a list head that nothing
\nelse iterates for this msk, and the entry leaks. kmemleak reports both
\nmptcp_pm_add_addr objects (from mptcp_pm_announced_alloc()) and
\nmptcp_pm_addr_entry objects (from
\nmptcp_userspace_pm_append_new_local_addr()) under sustained concurrent
\nANNOUNCE + close load against the userspace PM.<\/p>\n
Add an MPTCP_PM_DESTROYING bit in msk->pm.status, set by
\nmptcp_pm_destroy() under pm.lock before the lists are emptied and
\nchecked under pm.lock by the alloc paths. Either the alloc takes pm.lock
\nfirst, in which case its entry is on the list when mptcp_pm_destroy()
\nfrees it; or mptcp_pm_destroy() takes pm.lock first, in which case the
\nlater alloc observes the bit and refuses.<\/p>\n
Found by an MPTCP protocol-flow harness extending BRF (arXiv:2305.08782).<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
mptcp: pm: fix memory leak from alloc-during-teardown race<\/p>\n
mptcp_pm_destroy() empties msk->pm.anno_list and
\nmsk->pm.userspace_pm_l<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-17288","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/17288","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=17288"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=17288"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=17288"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}