{"cve":"CVE-2026-97958","nvd":{"published":"2026-09-25T11:17:23.477","modified":"2026-10-19T10:17:47.123","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_api: Don't replay RTM_GETCHAIN in tc_ctl_chain().\n\nIf a netlink socket sends RTM_GETCHAIN requests repeatedly\nwithout recv()ing the responses, tc_ctl_chain() hogs CPU and\ntriggers Hung Task splat. [0]\n\nAs caught in the stack trace, netlink_attachskb() could confuse\ntc_ctl_chain() by returning -EAGAIN when the userspace netlink\nsocket's receive buffer is full.\n\nThe replay: label exists since commit 32a4f5ecd738 (\"net: sched:\nintroduce chain object to uapi\") but was not used initially.\n\nSince commit 9f407f1768d3 (\"net: sched: introduce chain templates\"),\nthe label is needed for RTM_NEWCHAIN because tcf_proto_lookup_ops()\nmay release RTNL to call request_module().\n\nHowever, the replay logic is unnecessary for RTM_GETCHAIN.\n\nLet's apply the replay logic only for RTM_NEWCHAIN.\n\n[0]:\nINFO: task repro:1018 is blocked on a mutex likely owned by task repro:1022.\ntask:repro           state:R  running task     stack:14096 pid:1022  tgid:1014  ppid:961    task_flags:0x400040 flags:0x00080000\nCall Trace:\n <TASK>\n ? clockevents_program_event (kernel/time/clockevents.c:372)\n ? pskb_expand_head (net/core/skbuff.c:615)\n ? skb_release_data (net/core/skbuff.c:1122)\n ? netlink_attachskb (./include/linux/skbuff.h:1323 ./include/linux/skbuff.h:1332 net/netlink/af_netlink.c:1232)\n ? __netlink_lookup (./include/linux/rcupdate.h:882 ./include/linux/rhashtable.h:711 net/netlink/af_netlink.c:499)\n ? tc_chain_notify (net/sched/cls_api.c:3045)\n ? tc_chain_notify (./include/linux/skbuff.h:1384 net/sched/cls_api.c:3041)\n ? netlink_unicast (net/netlink/af_netlink.c:1335)\n ? rtnl_unicast (./include/net/netlink.h:1198 net/core/rtnetlink.c:985)\n ? tc_ctl_chain (net/sched/cls_api.c:3242)\n ? rtnetlink_rcv_msg (net/core/rtnetlink.c:7146)\n ? netlink_unicast (net/netlink/af_netlink.c:1354)\n ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:7177)\n ? netlink_rcv_skb (net/netlink/af_netlink.c:2556)\n ? netlink_unicast (net/netlink/af_netlink.c:1319)\n ? netlink_sendmsg (net/netlink/af_netlink.c:1900)\n ? __sock_sendmsg (net/socket.c:800)\n ? __sys_sendto (net/socket.c:2281)\n ? __x64_sys_sendto (net/socket.c:2288 net/socket.c:2284 net/socket.c:2284)\n ? do_syscall_64 (arch/x86/entry/syscall_64.c:61 arch/x86/entry/syscall_64.c:84)\n ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n </TASK>","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/240251a4ca7cda213103694b6e21c4a5745e5d8b","https://git.kernel.org/stable/c/503ba58481e3ba69d28127d35a39cec529f9670c","https://git.kernel.org/stable/c/6558b0d46c5941ed1aa67da8878e224c54239cc5","https://git.kernel.org/stable/c/96c2fc5daf983af2e0c1256c31e89c1f3f855279","https://git.kernel.org/stable/c/9a0f07f7dbd1bfe8c2fd03ad055e9e60a703d5df"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-97958","score":0.00177,"percentile":0.07145,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}