{"id":"CVE-2026-97958","title":"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_cha…","summary":"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_cha…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-835"],"vendor":"Linux","product":"Linux","affected":["Linux >= 2ed9db3074fcd8d12709fe40ff0e691d74229818 < 240251a4ca7cda213103694b6e21c4a5745e5d8b","Linux >= 2ed9db3074fcd8d12709fe40ff0e691d74229818 < 9a0f07f7dbd1bfe8c2fd03ad055e9e60a703d5df","Linux >= 2ed9db3074fcd8d12709fe40ff0e691d74229818 < 6558b0d46c5941ed1aa67da8878e224c54239cc5","Linux >= 2ed9db3074fcd8d12709fe40ff0e691d74229818 < 96c2fc5daf983af2e0c1256c31e89c1f3f855279","Linux >= 2ed9db3074fcd8d12709fe40ff0e691d74229818 < a1c2840d95af1fa3d83ba71e23fa0c674a4c6796","Linux >= 2ed9db3074fcd8d12709fe40ff0e691d74229818 < 503ba58481e3ba69d28127d35a39cec529f9670c","Linux >= 2ed9db3074fcd8d12709fe40ff0e691d74229818 < e9ac395bb56122a057d0aa91a6b55d9e3fa37c26","Linux >= 2ed9db3074fcd8d12709fe40ff0e691d74229818 < dff39930ad5e53d202bfdfb14687d1d2fd753b4d","Linux 4.19"],"published":"2026-09-25","updated":"2026-10-03","sourceUpdated":"2026-10-03T11:18:20.930","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97958","references":[{"url":"https://git.kernel.org/stable/c/240251a4ca7cda213103694b6e21c4a5745e5d8b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/503ba58481e3ba69d28127d35a39cec529f9670c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6558b0d46c5941ed1aa67da8878e224c54239cc5","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/96c2fc5daf983af2e0c1256c31e89c1f3f855279","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9a0f07f7dbd1bfe8c2fd03ad055e9e60a703d5df","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a1c2840d95af1fa3d83ba71e23fa0c674a4c6796","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dff39930ad5e53d202bfdfb14687d1d2fd753b4d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e9ac395bb56122a057d0aa91a6b55d9e3fa37c26","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97958.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-97958"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541096"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97958"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97958"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97958.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00177,"epssPercentile":0.07173,"cvssSource":"vendor","ingestedAt":"2026-09-25T11:06:38.875Z","slug":"CVE-2026-97958","body":"## Overview\n\nIn 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>\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, … · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97958.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":213397,"id":"CVE-2026-97958","ts":1790754704836,"field":"cvss","old":null,"new":"5.5"},{"seq":213396,"id":"CVE-2026-97958","ts":1790754704836,"field":"severity","old":"none","new":"medium"}]}