{"affected":[{"defaultStatus":"unaffected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"lessThan":"ec2501e361b08b50bcb1e7b3253fc861abbda28d","status":"affected","version":"665338b2a7a0139337d1f85be65ed16e487f84c1","versionType":"git"},{"lessThan":"d02e2fbf60de46678e2ea698a6a904fd21e1cc31","status":"affected","version":"665338b2a7a0139337d1f85be65ed16e487f84c1","versionType":"git"},{"lessThan":"48b26d48e76221dc90b02bf5428bab53643461ca","status":"affected","version":"665338b2a7a0139337d1f85be65ed16e487f84c1","versionType":"git"},{"lessThan":"8f1ff8866cb9f655e5faea6994eb902960be8e04","status":"affected","version":"665338b2a7a0139337d1f85be65ed16e487f84c1","versionType":"git"},{"lessThan":"3d07ca5c0fae311226f737963984bd94bb159a87","status":"affected","version":"665338b2a7a0139337d1f85be65ed16e487f84c1","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"status":"affected","version":"6.6"},{"lessThan":"6.6","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.141","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.91","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.33","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.10","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1","versionType":"original_commit_for_fix"}]}],"cveId":"CVE-2026-45845","cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: taprio: fix NULL pointer dereference in class dump\n\nWhen a TAPRIO child qdisc is deleted via RTM_DELQDISC, taprio_graft()\nis called with new == NULL and stores NULL into q->qdiscs[cl - 1].\nSubsequent RTM_GETTCLASS dump operations walk all classes via\ntaprio_walk() and call taprio_dump_class(), which calls taprio_leaf()\nreturning the NULL pointer, then dereferences it to read child->handle,\ncausing a kernel NULL pointer dereference.\n\nThe bug is reachable with namespace-scoped CAP_NET_ADMIN on any kernel\nwith CONFIG_NET_SCH_TAPRIO enabled. On systems with unprivileged user\nnamespaces enabled, an unprivileged local user can trigger a kernel\npanic by creating a taprio qdisc inside a new network namespace,\ngrafting an explicit child qdisc, deleting it, and requesting a class\ndump. The RTM_GETTCLASS dump itself requires no capability.\n\n Oops: general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] SMP KASAN NOPTI\n KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]\n RIP: 0010:taprio_dump_class (net/sched/sch_taprio.c:2478)\n Call Trace:\n  <TASK>\n  tc_fill_tclass (net/sched/sch_api.c:1966)\n  qdisc_class_dump (net/sched/sch_api.c:2326)\n  taprio_walk (net/sched/sch_taprio.c:2514)\n  tc_dump_tclass_qdisc (net/sched/sch_api.c:2352)\n  tc_dump_tclass_root (net/sched/sch_api.c:2370)\n  tc_dump_tclass (net/sched/sch_api.c:2431)\n  rtnl_dumpit (net/core/rtnetlink.c:6864)\n  netlink_dump (net/netlink/af_netlink.c:2325)\n  rtnetlink_rcv_msg (net/core/rtnetlink.c:6959)\n  netlink_rcv_skb (net/netlink/af_netlink.c:2550)\n  </TASK>\n\nFix this by substituting &noop_qdisc when new is NULL in\ntaprio_graft(), a common pattern used by other qdiscs (e.g.,\nmultiq_graft()) to ensure the q->qdiscs[] slots are never NULL.\nThis makes control-plane dump paths safe without requiring individual\nNULL checks.\n\nSince the data-plane paths (taprio_enqueue and taprio_dequeue_from_txq)\npreviously had explicit NULL guards that would drop/skip the packet\ncleanly, update those checks to test for &noop_qdisc instead. Without\nthis, packets would reach taprio_enqueue_one() which increments the root\nqdisc's qlen and backlog before calling the child's enqueue; noop_qdisc\ndrops the packet but those counters are never rolled back, permanently\ninflating the root qdisc's statistics.\n\nAfter this change *old can be a valid qdisc, NULL, or &noop_qdisc.\nOnly call qdisc_put(*old) in the first case to avoid decreasing\nnoop_qdisc's refcount, which was never increased.","epss":{"date":"2026-11-06","percentile":0.01815,"score":0.0012},"exploits":[],"kev":null,"metrics":[],"modifiedAt":1793979779407,"publishedAt":1779873888438,"references":[{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/ec2501e361b08b50bcb1e7b3253fc861abbda28d"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/d02e2fbf60de46678e2ea698a6a904fd21e1cc31"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/48b26d48e76221dc90b02bf5428bab53643461ca"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/8f1ff8866cb9f655e5faea6994eb902960be8e04"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/3d07ca5c0fae311226f737963984bd94bb159a87"}],"remediation":[],"revision":"e29a5d82c80e025eaa531cb65fcad2d0fbe4f38c64267e048ac563dcb1fdc363","sources":[{"modifiedAt":1793979779407,"name":"CNA: Linux","retrievedAt":1793981744795,"url":"https://www.cve.org/CVERecord?id=CVE-2026-45845"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793981758997,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-45845"}],"ssvc":{"assessedAt":1793979719608,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"net/sched: taprio: fix NULL pointer dereference in class dump","updatedAt":1793981758997}