In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
can: isotp: serialize TX state transitions under so->rx_lock<\/p>\n
The TX state machine (so->tx.state) is driven from three contexts:
\nsendmsg() claiming and progressing a transfer, the RX path consuming
\nFlow Control\/echo frames, and two hrtimers timing out a stalled
\ntransfer. Mixing a lock-free cmpxchg() claim in sendmsg() with
\nhrtimer_cancel() calls made under so->rx_lock elsewhere left windows
\nwhere a frame or timer callback could act on a state that had already
\nmoved on, corrupting an unrelated transfer.<\/p>\n
so->rx_lock now covers the full lifecycle of a TX claim: sendmsg()
\ntakes it to check so->tx.state is ISOTP_IDLE, switch it to
\nISOTP_SENDING, bump so->tx_gen and drain the previous transfer’s
\ntimers – all as one critical section. isotp_rcv_fc()\/isotp_rcv_cf()
\nalready run under this lock via isotp_rcv(), and isotp_rcv_echo() now
\ntakes it itself, so none of them can ever observe a transfer mid-claim.
\nThis also means a transfer can no longer be handed to sendmsg()’s
\ncleanup paths (signal or send error) while another thread is
\nconcurrently claiming or finishing it, so those paths can cancel
\ntimers and reset the state unconditionally.<\/p>\n
isotp_release() claims the socket the same way, so a racing sendmsg()
\nsees a consistent ISOTP_SHUTDOWN and skips arming its timer or sending.<\/p>\n
Only the hrtimer callbacks stay outside so->rx_lock, since they run
\nunder so->rx_lock’s cancellation elsewhere and taking it themselves
\nwould deadlock. so->tx_gen lets them recognize whether the transfer
\nthey timed out is still the one currently active, so they don’t
\nreport an error against a transfer that has since completed or been
\nsuperseded.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
can: isotp: serialize TX state transitions under so->rx_lock<\/p>\n
The TX state machine (so->tx.state) is driven from three contexts:
\nse<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-6790","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/6790","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=6790"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6790"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6790"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}