{"id":"CVE-2026-52997","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_dualpi2: drain both C-queue and L-queue in dualpi2_change()\n\nFix dualpi2_change() to correctly enforce updated limit and memlimit\nvalues after a configur…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_dualpi2: drain both C-queue and L-queue in dualpi2_change()\n\nFix dualpi2_change() to correctly enforce updated limit and memlimit\nvalues after a configur…","severity":"none","published":"2026-06-24","updated":"2026-07-10","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-52997","references":[{"url":"https://git.kernel.org/stable/c/3042add80c2c50bd127d570b83319af612efde65","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/478ed6b7d2577439c610f91fa8759a4c878a4264","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/86cf2eba2056bcf9c41fba260e599bd95bf9943b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00126,"epssPercentile":0.02651,"ingestedAt":"2026-07-11T13:13:25.707Z","slug":"CVE-2026-52997","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_dualpi2: drain both C-queue and L-queue in dualpi2_change()\n\nFix dualpi2_change() to correctly enforce updated limit and memlimit\nvalues after a configuration change of the dualpi2 qdisc.\n\nBefore this patch, dualpi2_change() always attempted to dequeue packets\nvia the root qdisc (C-queue) when reducing backlog or memory usage, and\nunconditionally assumed that a valid skb will be returned. When traffic\nclassification results in packets being queued in the L-queue while the\nC-queue is empty, this leads to a NULL skb dereference during limit or\nmemlimit enforcement.\n\nThis is fixed by first dequeuing from the C-queue path if it is\nnon-empty. Once the C-queue is empty, packets are dequeued directly from\nthe L-queue. Return values from qdisc_dequeue_internal() are checked for\nboth queues. When dequeuing from the L-queue, the parent qdisc qlen and\nbacklog counters are updated explicitly to keep overall qdisc statistics\nconsistent.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}