{"id":"CVE-2025-68815","summary":"net/sched: ets: Remove drr class from the active list if it changes to strict","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: ets: Remove drr class from the active list if it changes to strict\n\nWhenever a user issues an ets qdisc change command, transforming a\ndrr class into a strict one, the ets code isn't checking whether that\nclass was in the active list and removing it. This means that, if a\nuser changes a strict class (which was in the active list) back to a drr\none, that class will be added twice to the active list [1].\n\nDoing so with the following commands:\n\ntc qdisc add dev lo root handle 1: ets bands 2 strict 1\ntc qdisc add dev lo parent 1:2 handle 20: \\\n    tbf rate 8bit burst 100b latency 1s\ntc filter add dev lo parent 1: basic classid 1:2\nping -c1 -W0.01 -s 56 127.0.0.1\ntc qdisc change dev lo root handle 1: ets bands 2 strict 2\ntc qdisc change dev lo root handle 1: ets bands 2 strict 1\nping -c1 -W0.01 -s 56 127.0.0.1\n\nWill trigger the following splat with list debug turned on:\n\n[   59.279014][  T365] ------------[ cut here ]------------\n[   59.279452][  T365] list_add double add: new=ffff88801d60e350, prev=ffff88801d60e350, next=ffff88801d60e2c0.\n[   59.280153][  T365] WARNING: CPU: 3 PID: 365 at lib/list_debug.c:35 __list_add_valid_or_report+0x17f/0x220\n[   59.280860][  T365] Modules linked in:\n[   59.281165][  T365] CPU: 3 UID: 0 PID: 365 Comm: tc Not tainted 6.18.0-rc7-00105-g7e9f13163c13-dirty #239 PREEMPT(voluntary)\n[   59.281977][  T365] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011\n[   59.282391][  T365] RIP: 0010:__list_add_valid_or_report+0x17f/0x220\n[   59.282842][  T365] Code: 89 c6 e8 d4 b7 0d ff 90 0f 0b 90 90 31 c0 e9 31 ff ff ff 90 48 c7 c7 e0 a0 22 9f 48 89 f2 48 89 c1 4c 89 c6 e8 b2 b7 0d ff 90 \u003c0f\u003e 0b 90 90 31 c0 e9 0f ff ff ff 48 89 f7 48 89 44 24 10 4c 89 44\n...\n[   59.288812][  T365] Call Trace:\n[   59.289056][  T365]  \u003cTASK\u003e\n[   59.289224][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   59.289546][  T365]  ets_qdisc_change+0xd2b/0x1e80\n[   59.289891][  T365]  ? __lock_acquire+0x7e7/0x1be0\n[   59.290223][  T365]  ? __pfx_ets_qdisc_change+0x10/0x10\n[   59.290546][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   59.290898][  T365]  ? __mutex_trylock_common+0xda/0x240\n[   59.291228][  T365]  ? __pfx___mutex_trylock_common+0x10/0x10\n[   59.291655][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   59.291993][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   59.292313][  T365]  ? trace_contention_end+0xc8/0x110\n[   59.292656][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   59.293022][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   59.293351][  T365]  tc_modify_qdisc+0x63a/0x1cf0\n\nFix this by always checking and removing an ets class from the active list\nwhen changing it to strict.\n\n[1] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/tree/net/sched/sch_ets.c?id=ce052b9402e461a9aded599f5b47e76bc727f7de#n663","modified":"2026-10-28T02:30:54.833061683Z","published":"2026-01-13T15:29:19.789Z","related":["SUSE-SU-2026:0447-1","SUSE-SU-2026:0472-1","SUSE-SU-2026:0587-1","SUSE-SU-2026:20477-1","SUSE-SU-2026:20498-1","SUSE-SU-2026:20555-1","SUSE-SU-2026:20570-1","SUSE-SU-2026:20599-1","SUSE-SU-2026:20615-1","SUSE-SU-2026:20845-1","SUSE-SU-2026:20876-1","openSUSE-SU-2026:20287-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68815.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/02783a37cb1c0a2bd9fcba4ff1b81e6e209c7d87"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2f125ebe47d6369e562f3cbd9b6227cff51eaf34"},{"type":"WEB","url":"https://git.kernel.org/stable/c/43d9a530c8c094d137159784e7c951c65f11ec6c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/58fdce6bc005e964f1dbc3ca716f5fe0f68839a2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8067db5c95aab9461d23117679338cd8869831fa"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b1e125ae425aba9b45252e933ca8df52a843ec70"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cca2ed931b734fe48139bc6f020e47367346630f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68815.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-68815"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"f517335a61ff8037b18ba1b0a002c1f82926a934"},{"fixed":"58fdce6bc005e964f1dbc3ca716f5fe0f68839a2"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"cd9b50adc6bb9ad3f7d244590a389522215865c4"},{"fixed":"02783a37cb1c0a2bd9fcba4ff1b81e6e209c7d87"},{"fixed":"8067db5c95aab9461d23117679338cd8869831fa"},{"fixed":"2f125ebe47d6369e562f3cbd9b6227cff51eaf34"},{"fixed":"cca2ed931b734fe48139bc6f020e47367346630f"},{"fixed":"43d9a530c8c094d137159784e7c951c65f11ec6c"},{"fixed":"b1e125ae425aba9b45252e933ca8df52a843ec70"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.10.62"},{"fixed":"5.10.248"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.13.14"},{"fixed":"5.14"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"d05330672afe2e142ba97e63bd7c1faef76781bb"}]}],"versions":["v5.10.247","v5.10.246","v5.10.245","v5.10.244","v5.10.243","v5.10.242","v5.10.241","v5.10.240","v5.10.239","v5.10.238","v5.10.237","v5.10.236","v5.10.235","v5.10.234","v5.10.233","v5.10.232","v5.10.231","v5.10.230","v5.10.229","v5.10.228","v5.10.227","v5.10.226","v5.10.225","v5.10.224","v5.10.223","v5.10.222","v5.10.221","v5.10.220","v5.10.219","v5.10.218","v5.10.217","v5.10.216","v5.10.215","v5.10.214","v5.10.213","v5.10.212","v5.10.211","v5.10.210","v5.10.209","v5.10.208","v5.10.207","v5.10.206","v5.10.205","v5.10.204","v5.10.203","v5.10.202","v5.10.201","v5.10.200","v5.10.199","v5.10.198","v5.10.197","v5.10.196","v5.10.195","v5.10.194","v5.10.193","v5.10.192","v5.10.191","v5.10.190","v5.10.189","v5.10.188","v5.10.187","v5.10.186","v5.10.185","v5.10.184","v5.10.183","v5.10.182","v5.10.181","v5.10.180","v5.10.179","v5.10.178","v5.10.177","v5.10.176","v5.10.175","v5.10.174","v5.10.173","v5.10.172","v5.10.171","v5.10.170","v5.10.169","v5.10.168","v5.10.167","v5.10.166","v5.10.165","v5.10.164","v5.10.163","v5.10.162","v5.10.161","v5.10.160","v5.10.159","v5.10.158","v5.10.157","v5.10.156","v5.10.155","v5.10.154","v5.10.153","v5.10.152","v5.10.151","v5.10.150","v5.10.149","v5.10.148","v5.10.147","v5.10.146","v5.10.145","v5.10.144","v5.10.143","v5.10.142","v5.10.141","v5.10.140","v5.10.139","v5.10.138","v5.10.137","v5.10.136","v5.10.135","v5.10.134","v5.10.133","v5.10.132","v5.10.131","v5.10.130","v5.10.129","v5.10.128","v5.10.127","v5.10.126","v5.10.125","v5.10.124","v5.10.123","v5.10.122","v5.10.121","v5.10.120","v5.10.119","v5.10.118","v5.10.117","v5.10.116","v5.10.115","v5.10.114","v5.10.113","v5.10.112","v5.10.111","v5.10.110","v5.10.109","v5.10.108","v5.10.107","v5.10.106","v5.10.105","v5.10.104","v5.10.103","v5.10.102","v5.10.101","v5.10.100","v5.10.99","v5.10.98","v5.10.97","v5.10.96","v5.10.95","v5.10.94","v5.10.93","v5.10.92","v5.10.91","v5.10.90","v5.10.89","v5.10.88","v5.10.87","v5.10.86","v5.10.85","v5.10.84","v5.10.83","v5.10.82","v5.10.81","v5.10.80","v5.10.79","v5.10.78","v5.10.77","v5.10.76","v5.10.75","v5.10.74","v5.10.73","v5.10.72","v5.10.71","v5.10.70","v5.10.69","v5.10.68","v5.10.67","v5.10.66","v5.10.65","v5.10.64","v5.10.63","v5.10.62","v5.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