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Linux Distros Unpatched Vulnerability : CVE-2026-45845
medium Nessus Plugin ID 317081
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Synopsis
The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.Description
The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.- net/sched: taprio: fix NULL pointer dereference in class dump When a TAPRIO child qdisc is deleted via RTM_DELQDISC, taprio_graft() is called with new == NULL and stores NULL into q->qdiscs[cl - 1]. Subsequent RTM_GETTCLASS dump operations walk all classes via taprio_walk() and call taprio_dump_class(), which calls taprio_leaf() returning the NULL pointer, then dereferences it to read child->handle, causing a kernel NULL pointer dereference. The bug is reachable with namespace-scoped CAP_NET_ADMIN on any kernel with CONFIG_NET_SCH_TAPRIO enabled. On systems with unprivileged user namespaces enabled, an unprivileged local user can trigger a kernel panic by creating a taprio qdisc inside a new network namespace, grafting an explicit child qdisc, deleting it, and requesting a class dump. The RTM_GETTCLASS dump itself requires no capability. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP:
0010:taprio_dump_class (net/sched/sch_taprio.c:2478) Call Trace: <TASK> tc_fill_tclass (net/sched/sch_api.c:1966) qdisc_class_dump (net/sched/sch_api.c:2326) taprio_walk (net/sched/sch_taprio.c:2514) tc_dump_tclass_qdisc (net/sched/sch_api.c:2352) tc_dump_tclass_root (net/sched/sch_api.c:2370) tc_dump_tclass (net/sched/sch_api.c:2431) rtnl_dumpit (net/core/rtnetlink.c:6864) netlink_dump (net/netlink/af_netlink.c:2325) rtnetlink_rcv_msg (net/core/rtnetlink.c:6959) netlink_rcv_skb (net/netlink/af_netlink.c:2550) </TASK> Fix this by substituting &noop_qdisc when new is NULL in taprio_graft(), a common pattern used by other qdiscs (e.g., multiq_graft()) to ensure the q->qdiscs[] slots are never NULL. This makes control-plane dump paths safe without requiring individual NULL checks. Since the data-plane paths (taprio_enqueue and taprio_dequeue_from_txq) previously had explicit NULL guards that would drop/skip the packet cleanly, update those checks to test for &noop_qdisc instead. Without this, packets would reach taprio_enqueue_one() which increments the root qdisc's qlen and backlog before calling the child's enqueue; noop_qdisc drops the packet but those counters are never rolled back, permanently inflating the root qdisc's statistics. After this change *old can be a valid qdisc, NULL, or &noop_qdisc. Only call qdisc_put(*old) in the first case to avoid decreasing noop_qdisc's refcount, which was never increased.
(CVE-2026-45845)
Note that Nessus relies on the presence of the package as reported by the vendor.
Solution
There is no known solution at this time.See Also
Plugin Details
Severity: Medium
ID: 317081
File Name: unpatched_CVE_2026_45845.nasl
Version: 1.1
Type: Local
Agent: unix
Family: Misc.
Published: 5/27/2026
Updated: 5/27/2026
Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 4.4
CVSS v2
Risk Factor: Medium
Base Score: 4.9
Temporal Score: 4.2
Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C
CVSS Score Source: CVE-2026-45845
CVSS v3
Risk Factor: Medium
Base Score: 5.5
Temporal Score: 5.1
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C
Vulnerability Information
CPE: p-cpe:/a:redhat:enterprise_linux:kernel-rt-selftests-internal, p-cpe:/a:redhat:enterprise_linux:kernel-modules-partner, cpe:/o:debian:debian_linux:14.0, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules, p-cpe:/a:redhat:enterprise_linux:kernel-debug, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules, p-cpe:/a:redhat:enterprise_linux:kernel-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-tools, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-core, p-cpe:/a:redhat:enterprise_linux:bpftool, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug, p-cpe:/a:redhat:enterprise_linux:kernel-rt-core, p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-uki-virt-addons, p-cpe:/a:redhat:enterprise_linux:kernel-64k, p-cpe:/a:redhat:enterprise_linux:rtla, p-cpe:/a:redhat:enterprise_linux:kernel-ipaclones-internal, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-extra, p-cpe:/a:redhat:enterprise_linux:python3-perf, p-cpe:/a:redhat:enterprise_linux:kernel-rt, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-partner, p-cpe:/a:debian:debian_linux:linux, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-extra, cpe:/o:redhat:enterprise_linux:10, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:perf, p-cpe:/a:redhat:enterprise_linux:kernel-abi-stablelists, p-cpe:/a:redhat:enterprise_linux:kernel-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs-devel, p-cpe:/a:redhat:enterprise_linux:kernel-cross-headers, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-devel-matched, p-cpe:/a:redhat:enterprise_linux:rv, cpe:/o:debian:debian_linux:13.0, p-cpe:/a:redhat:enterprise_linux:kernel-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-core, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:redhat:enterprise_linux:libperf-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs, p-cpe:/a:redhat:enterprise_linux:kernel-uki-virt, p-cpe:/a:redhat:enterprise_linux:libperf, p-cpe:/a:redhat:enterprise_linux:kernel-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-headers, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-64k-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-64k-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-modules-extra-matched, p-cpe:/a:redhat:enterprise_linux:kernel-debug-uki-virt, p-cpe:/a:redhat:enterprise_linux:kernel-doc, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-debug-uki-virt-addons, p-cpe:/a:redhat:enterprise_linux:kernel-selftests-internal, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-devel, p-cpe:/a:redhat:enterprise_linux:kernel-64k-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-internal
Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier
Exploit Ease: No known exploits are available
Vulnerability Publication Date: 5/27/2026
Reference Information
CVE: CVE-2026-45845