{"id":"AZL-53855","summary":"CVE-2024-53057 affecting package kernel for versions less than 6.6.64.2-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: stop qdisc_tree_reduce_backlog on TC_H_ROOT\n\nIn qdisc_tree_reduce_backlog, Qdiscs with major handle ffff: are assumed\nto be either root or ingress. This assumption is bogus since it's valid\nto create egress qdiscs with major handle ffff:\nBudimir Markovic found that for qdiscs like DRR that maintain an active\nclass list, it will cause a UAF with a dangling class pointer.\n\nIn 066a3b5b2346, the concern was to avoid iterating over the ingress\nqdisc since its parent is itself. The proper fix is to stop when parent\nTC_H_ROOT is reached because the only way to retrieve ingress is when a\nhierarchy which does not contain a ffff: major handle call into\nqdisc_lookup with TC_H_MAJ(TC_H_ROOT).\n\nIn the scenario where major ffff: is an egress qdisc in any of the tree\nlevels, the updates will also propagate to TC_H_ROOT, which then the\niteration must stop.\n\n\n net/sched/sch_api.c | 2 +-\n 1 file changed, 1 insertion(+), 1 deletion(-)","modified":"2026-04-01T05:18:08.699948Z","published":"2024-11-19T18:15:25Z","upstream":["CVE-2024-53057"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-53057"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.64.2-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-53855.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}