In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
veth: fix queue index used to wake the peer txq in veth_poll<\/p>\n
veth_poll() derives the index of the peer TX queue to wake from
\nrq->xdp_rxq.queue_index. That field is only initialized by
\nxdp_rxq_info_reg() in veth_enable_xdp_range(), which runs only when an
\nXDP program is attached. On the plain GRO\/NAPI path
\n(veth_napi_enable_range()) xdp_rxq_info_reg() is never called, so
\nqueue_index stays 0 for every queue, as priv->rq is zero-allocated.<\/p>\n
So in a multi-queue setup with GRO enabled and no XDP program attached,
\nevery NAPI instance looks at the peer’s TX queue 0. If veth_xmit() stops
\npeer TX queue 1 because the ptr_ring is full (NETDEV_TX_BUSY), nothing
\never wakes it again: the poller draining queue 1 wakes queue 0 instead.
\nveth implements no ndo_tx_timeout, so the netdev watchdog does not kick
\nin either, and the queue stays stopped indefinitely.<\/p>\n
Derive the index from the position of the rq within priv->rq instead,
\nwhich is correct regardless of whether XDP was ever enabled.<\/p>\n
Scripts to reproduce the stall are available at
\nhttps:\/\/github.com\/netoptimizer\/veth-backpressure-performance-testing<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
veth: fix queue index used to wake the peer txq in veth_poll<\/p>\n
veth_poll() derives the index of the peer TX queue to wake from
\nrq->x<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-11923","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/11923","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=11923"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11923"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11923"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}