In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/handshake: Drain pending requests at net namespace exit<\/p>\n
The arguments to list_splice_init() in handshake_net_exit() are
\nreversed. The call moves the local empty “requests” list onto
\nhn->hn_requests, leaving the local list empty, so the subsequent
\ndrain loop runs zero iterations. Pending handshake requests that
\nhad not yet been accepted are not torn down when the net namespace
\nis destroyed; each one keeps a reference on a socket file and on
\nthe handshake_req allocation.<\/p>\n
Pass the source and destination in the documented order
\n(list_splice_init(list, head) moves list onto head) so the pending
\nlist is transferred to the local scratch list and drained through
\nhandshake_complete().<\/p>\n
Fixing the splice direction exposes a list-corruption race. After
\nthe splice each req->hr_list still has non-empty link pointers,
\nthreading the stack-local scratch list rather than hn_requests.
\nA concurrent handshake_req_cancel() — for example, from sunrpc’s
\nTLS timeout on a kernel socket whose netns reference was not
\ntaken — finds the request through the rhashtable, calls
\nremove_pending(), and sees !list_empty(&req->hr_list).
\n__remove_pending_locked() then list_del_init()s an entry off the
\nscratch list while the drain iterates, corrupting it. The same
\ncall arriving after the drain loop has run list_del() on an
\nentry hits LIST_POISON instead.<\/p>\n
Have remove_pending() check HANDSHAKE_F_NET_DRAINING under
\nhn_lock and report not-found when drain is in progress. The
\ndrain has already taken ownership; handshake_complete()’s existing
\ntest_and_set on HANDSHAKE_F_REQ_COMPLETED still arbitrates
\nbetween drain and cancel for who calls the consumer’s hp_done. Use
\nlist_del_init() rather than list_del() in the drain so req->hr_list
\ndoes not carry LIST_POISON after drain releases the entry.<\/p>\n
The DRAINING guard in remove_pending() makes cancel return false,
\nbut cancel still falls through to test_and_set_bit on
\nHANDSHAKE_F_REQ_COMPLETED and drops the request’s hr_file reference.
\nWithout another pin, if that is the last reference, sk_destruct frees
\nthe request while it is still linked on the drain loop’s local list.
\nPin each request’s hr_file under hn_lock before releasing the list,
\nand drop that drain pin after the loop finishes with the request.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/handshake: Drain pending requests at net namespace exit<\/p>\n
The arguments to list_splice_init() in handshake_net_exit() are
\nrevers<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-14990","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/14990","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=14990"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14990"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14990"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}