In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/sched: hhf: clamp quantum before hhf_change() to avoid overflow<\/p>\n
hhf_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) with no overflow
\ncheck. A device with a huge MTU (e.g. dummy with max_mtu == 0 accepting
\nMTU 2147483634) makes weight * quantum overflow the signed deficit in
\nhhf_dequeue(), spinning forever.<\/p>\n
Clamp q->quantum before hhf_change() so both the opt and !opt paths see
\na sane quantum. Without this, bare “tc qdisc add … hhf” succeeds with
\na clamped quantum but “tc qdisc add … hhf limit 1000” (any option
\npresent) fails with -EINVAL because hhf_change() re-validates the
\nunclamped default (sch_hhf.c:559). 256 matches fq_codel’s floor and is
\na sane minimum for a DRR quantum.<\/p>\n
Conditions to recreate the bug: a device whose MTU (plus
\nhard_header_len) wraps psched_mtu() into the sign bit (e.g. a dummy
\ndevice with max_mtu == 0 accepting MTU 2147483634). Requires
\nCAP_NET_ADMIN in a user namespace.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/sched: hhf: clamp quantum before hhf_change() to avoid overflow<\/p>\n
hhf_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) with n<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-25482","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/25482","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=25482"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=25482"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=25482"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}