{"api_version":"1","generated_at":"2026-05-13T00:20:36+00:00","cve":"CVE-2025-38684","urls":{"html":"https://cve.report/CVE-2025-38684","api":"https://cve.report/api/cve/CVE-2025-38684.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2025-38684","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-38684"},"summary":{"title":"net/sched: ets: use old 'nbands' while purging unused classes","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: ets: use old 'nbands' while purging unused classes\n\nShuang reported sch_ets test-case [1] crashing in ets_class_qlen_notify()\nafter recent changes from Lion [2]. The problem is: in ets_qdisc_change()\nwe purge unused DWRR queues; the value of 'q->nbands' is the new one, and\nthe cleanup should be done with the old one. The problem is here since my\nfirst attempts to fix ets_qdisc_change(), but it surfaced again after the\nrecent qdisc len accounting fixes. Fix it purging idle DWRR queues before\nassigning a new value of 'q->nbands', so that all purge operations find a\nconsistent configuration:\n\n - old 'q->nbands' because it's needed by ets_class_find()\n - old 'q->nstrict' because it's needed by ets_class_is_strict()\n\n BUG: kernel NULL pointer dereference, address: 0000000000000000\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n PGD 0 P4D 0\n Oops: Oops: 0000 [#1] SMP NOPTI\n CPU: 62 UID: 0 PID: 39457 Comm: tc Kdump: loaded Not tainted 6.12.0-116.el10.x86_64 #1 PREEMPT(voluntary)\n Hardware name: Dell Inc. PowerEdge R640/06DKY5, BIOS 2.12.2 07/09/2021\n RIP: 0010:__list_del_entry_valid_or_report+0x4/0x80\n Code: ff 4c 39 c7 0f 84 39 19 8e ff b8 01 00 00 00 c3 cc cc cc cc 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <48> 8b 17 48 8b 4f 08 48 85 d2 0f 84 56 19 8e ff 48 85 c9 0f 84 ab\n RSP: 0018:ffffba186009f400 EFLAGS: 00010202\n RAX: 00000000000000d6 RBX: 0000000000000000 RCX: 0000000000000004\n RDX: ffff9f0fa29b69c0 RSI: 0000000000000000 RDI: 0000000000000000\n RBP: ffffffffc12c2400 R08: 0000000000000008 R09: 0000000000000004\n R10: ffffffffffffffff R11: 0000000000000004 R12: 0000000000000000\n R13: ffff9f0f8cfe0000 R14: 0000000000100005 R15: 0000000000000000\n FS:  00007f2154f37480(0000) GS:ffff9f269c1c0000(0000) knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 0000000000000000 CR3: 00000001530be001 CR4: 00000000007726f0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n PKRU: 55555554\n Call Trace:\n  <TASK>\n  ets_class_qlen_notify+0x65/0x90 [sch_ets]\n  qdisc_tree_reduce_backlog+0x74/0x110\n  ets_qdisc_change+0x630/0xa40 [sch_ets]\n  __tc_modify_qdisc.constprop.0+0x216/0x7f0\n  tc_modify_qdisc+0x7c/0x120\n  rtnetlink_rcv_msg+0x145/0x3f0\n  netlink_rcv_skb+0x53/0x100\n  netlink_unicast+0x245/0x390\n  netlink_sendmsg+0x21b/0x470\n  ____sys_sendmsg+0x39d/0x3d0\n  ___sys_sendmsg+0x9a/0xe0\n  __sys_sendmsg+0x7a/0xd0\n  do_syscall_64+0x7d/0x160\n  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n RIP: 0033:0x7f2155114084\n Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d 25 f0 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89\n RSP: 002b:00007fff1fd7a988 EFLAGS: 00000202 ORIG_RAX: 000000000000002e\n RAX: ffffffffffffffda RBX: 0000560ec063e5e0 RCX: 00007f2155114084\n RDX: 0000000000000000 RSI: 00007fff1fd7a9f0 RDI: 0000000000000003\n RBP: 00007fff1fd7aa60 R08: 0000000000000010 R09: 000000000000003f\n R10: 0000560ee9b3a010 R11: 0000000000000202 R12: 00007fff1fd7aae0\n R13: 000000006891ccde R14: 0000560ec063e5e0 R15: 00007fff1fd7aad0\n  </TASK>\n\n [1] https://lore.kernel.org/netdev/e08c7f4a6882f260011909a868311c6e9b54f3e4.1639153474.git.dcaratti@redhat.com/\n [2] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com/","state":"PUBLISHED","assigner":"Linux","published_at":"2025-09-04 16:15:36","updated_at":"2026-05-12 13:16:54"},"problem_types":["CWE-476"],"metrics":[{"version":"3.1","source":"nvd@nist.gov","type":"Primary","score":"5.5","severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}}],"references":[{"url":"https://git.kernel.org/stable/c/87c6efc5ce9c126ae4a781bc04504b83780e3650","name":"https://git.kernel.org/stable/c/87c6efc5ce9c126ae4a781bc04504b83780e3650","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/be9692dafdfb36d9c43afd9d4e1d9d9ba8e7b51b","name":"https://git.kernel.org/stable/c/be9692dafdfb36d9c43afd9d4e1d9d9ba8e7b51b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","name":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":["Third Party Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5b3b346bc4c2aa2c428735438a11989d251f32f1","name":"https://git.kernel.org/stable/c/5b3b346bc4c2aa2c428735438a11989d251f32f1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/97ec167cd2e8a81a2d87331a2ed92daf007542c8","name":"https://git.kernel.org/stable/c/97ec167cd2e8a81a2d87331a2ed92daf007542c8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/bdfddcde86e8b9245d9c0c2efe2b6fe8dcf6bf41","name":"https://git.kernel.org/stable/c/bdfddcde86e8b9245d9c0c2efe2b6fe8dcf6bf41","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d69f4a258cd91b3bcef7089eb0401005aae2aed5","name":"https://git.kernel.org/stable/c/d69f4a258cd91b3bcef7089eb0401005aae2aed5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-032379.html","name":"https://cert-portal.siemens.com/productcert/html/ssa-032379.html","refsource":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/970c1c731c4ede46d05f5b0355724d1e400cfbca","name":"https://git.kernel.org/stable/c/970c1c731c4ede46d05f5b0355724d1e400cfbca","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/84a24fb446ee07b22b64aae6f0e3f4a38266310a","name":"https://git.kernel.org/stable/c/84a24fb446ee07b22b64aae6f0e3f4a38266310a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html","name":"https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":["Third Party Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-38684","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38684","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 bdfddcde86e8b9245d9c0c2efe2b6fe8dcf6bf41 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 be9692dafdfb36d9c43afd9d4e1d9d9ba8e7b51b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 97ec167cd2e8a81a2d87331a2ed92daf007542c8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 84a24fb446ee07b22b64aae6f0e3f4a38266310a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 5b3b346bc4c2aa2c428735438a11989d251f32f1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 d69f4a258cd91b3bcef7089eb0401005aae2aed5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 970c1c731c4ede46d05f5b0355724d1e400cfbca git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 87c6efc5ce9c126ae4a781bc04504b83780e3650 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3b290923ad2b23596208c1e29520badef4356a43 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.6","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.6 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.241 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.190 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.149 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.103 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.43 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.15.11 6.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.16.2 6.16.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.17 * original_commit_for_fix","platforms":[]},{"source":"ADP","vendor":"Siemens","product":"SIMATIC CN 4100","version":"affected V5.0 custom","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2025","cve_id":"38684","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"linux","cpe5":"linux_kernel","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"providerMetadata":{"dateUpdated":"2025-11-03T17:41:11.527Z","orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE"},"references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"}],"title":"CVE Program Container"},{"affected":[{"defaultStatus":"unknown","product":"SIMATIC CN 4100","vendor":"Siemens","versions":[{"lessThan":"V5.0","status":"affected","version":"0","versionType":"custom"}]}],"providerMetadata":{"dateUpdated":"2026-05-12T12:05:24.841Z","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","shortName":"siemens-SADP"},"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-032379.html"}],"x_adpType":"supplier"}],"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/sched/sch_ets.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"bdfddcde86e8b9245d9c0c2efe2b6fe8dcf6bf41","status":"affected","version":"dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33","versionType":"git"},{"lessThan":"be9692dafdfb36d9c43afd9d4e1d9d9ba8e7b51b","status":"affected","version":"dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33","versionType":"git"},{"lessThan":"97ec167cd2e8a81a2d87331a2ed92daf007542c8","status":"affected","version":"dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33","versionType":"git"},{"lessThan":"84a24fb446ee07b22b64aae6f0e3f4a38266310a","status":"affected","version":"dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33","versionType":"git"},{"lessThan":"5b3b346bc4c2aa2c428735438a11989d251f32f1","status":"affected","version":"dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33","versionType":"git"},{"lessThan":"d69f4a258cd91b3bcef7089eb0401005aae2aed5","status":"affected","version":"dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33","versionType":"git"},{"lessThan":"970c1c731c4ede46d05f5b0355724d1e400cfbca","status":"affected","version":"dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33","versionType":"git"},{"lessThan":"87c6efc5ce9c126ae4a781bc04504b83780e3650","status":"affected","version":"dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33","versionType":"git"},{"status":"affected","version":"3b290923ad2b23596208c1e29520badef4356a43","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/sched/sch_ets.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.6"},{"lessThan":"5.6","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.241","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.190","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.149","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.103","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.43","versionType":"semver"},{"lessThanOrEqual":"6.15.*","status":"unaffected","version":"6.15.11","versionType":"semver"},{"lessThanOrEqual":"6.16.*","status":"unaffected","version":"6.16.2","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"6.17","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.241","versionStartIncluding":"5.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.190","versionStartIncluding":"5.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.149","versionStartIncluding":"5.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.103","versionStartIncluding":"5.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.43","versionStartIncluding":"5.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.15.11","versionStartIncluding":"5.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.16.2","versionStartIncluding":"5.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.17","versionStartIncluding":"5.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.296","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: ets: use old 'nbands' while purging unused classes\n\nShuang reported sch_ets test-case [1] crashing in ets_class_qlen_notify()\nafter recent changes from Lion [2]. The problem is: in ets_qdisc_change()\nwe purge unused DWRR queues; the value of 'q->nbands' is the new one, and\nthe cleanup should be done with the old one. The problem is here since my\nfirst attempts to fix ets_qdisc_change(), but it surfaced again after the\nrecent qdisc len accounting fixes. Fix it purging idle DWRR queues before\nassigning a new value of 'q->nbands', so that all purge operations find a\nconsistent configuration:\n\n - old 'q->nbands' because it's needed by ets_class_find()\n - old 'q->nstrict' because it's needed by ets_class_is_strict()\n\n BUG: kernel NULL pointer dereference, address: 0000000000000000\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n PGD 0 P4D 0\n Oops: Oops: 0000 [#1] SMP NOPTI\n CPU: 62 UID: 0 PID: 39457 Comm: tc Kdump: loaded Not tainted 6.12.0-116.el10.x86_64 #1 PREEMPT(voluntary)\n Hardware name: Dell Inc. PowerEdge R640/06DKY5, BIOS 2.12.2 07/09/2021\n RIP: 0010:__list_del_entry_valid_or_report+0x4/0x80\n Code: ff 4c 39 c7 0f 84 39 19 8e ff b8 01 00 00 00 c3 cc cc cc cc 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <48> 8b 17 48 8b 4f 08 48 85 d2 0f 84 56 19 8e ff 48 85 c9 0f 84 ab\n RSP: 0018:ffffba186009f400 EFLAGS: 00010202\n RAX: 00000000000000d6 RBX: 0000000000000000 RCX: 0000000000000004\n RDX: ffff9f0fa29b69c0 RSI: 0000000000000000 RDI: 0000000000000000\n RBP: ffffffffc12c2400 R08: 0000000000000008 R09: 0000000000000004\n R10: ffffffffffffffff R11: 0000000000000004 R12: 0000000000000000\n R13: ffff9f0f8cfe0000 R14: 0000000000100005 R15: 0000000000000000\n FS:  00007f2154f37480(0000) GS:ffff9f269c1c0000(0000) knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 0000000000000000 CR3: 00000001530be001 CR4: 00000000007726f0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n PKRU: 55555554\n Call Trace:\n  <TASK>\n  ets_class_qlen_notify+0x65/0x90 [sch_ets]\n  qdisc_tree_reduce_backlog+0x74/0x110\n  ets_qdisc_change+0x630/0xa40 [sch_ets]\n  __tc_modify_qdisc.constprop.0+0x216/0x7f0\n  tc_modify_qdisc+0x7c/0x120\n  rtnetlink_rcv_msg+0x145/0x3f0\n  netlink_rcv_skb+0x53/0x100\n  netlink_unicast+0x245/0x390\n  netlink_sendmsg+0x21b/0x470\n  ____sys_sendmsg+0x39d/0x3d0\n  ___sys_sendmsg+0x9a/0xe0\n  __sys_sendmsg+0x7a/0xd0\n  do_syscall_64+0x7d/0x160\n  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n RIP: 0033:0x7f2155114084\n Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d 25 f0 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89\n RSP: 002b:00007fff1fd7a988 EFLAGS: 00000202 ORIG_RAX: 000000000000002e\n RAX: ffffffffffffffda RBX: 0000560ec063e5e0 RCX: 00007f2155114084\n RDX: 0000000000000000 RSI: 00007fff1fd7a9f0 RDI: 0000000000000003\n RBP: 00007fff1fd7aa60 R08: 0000000000000010 R09: 000000000000003f\n R10: 0000560ee9b3a010 R11: 0000000000000202 R12: 00007fff1fd7aae0\n R13: 000000006891ccde R14: 0000560ec063e5e0 R15: 00007fff1fd7aad0\n  </TASK>\n\n [1] https://lore.kernel.org/netdev/e08c7f4a6882f260011909a868311c6e9b54f3e4.1639153474.git.dcaratti@redhat.com/\n [2] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com/"}],"providerMetadata":{"dateUpdated":"2026-05-11T21:32:58.875Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/bdfddcde86e8b9245d9c0c2efe2b6fe8dcf6bf41"},{"url":"https://git.kernel.org/stable/c/be9692dafdfb36d9c43afd9d4e1d9d9ba8e7b51b"},{"url":"https://git.kernel.org/stable/c/97ec167cd2e8a81a2d87331a2ed92daf007542c8"},{"url":"https://git.kernel.org/stable/c/84a24fb446ee07b22b64aae6f0e3f4a38266310a"},{"url":"https://git.kernel.org/stable/c/5b3b346bc4c2aa2c428735438a11989d251f32f1"},{"url":"https://git.kernel.org/stable/c/d69f4a258cd91b3bcef7089eb0401005aae2aed5"},{"url":"https://git.kernel.org/stable/c/970c1c731c4ede46d05f5b0355724d1e400cfbca"},{"url":"https://git.kernel.org/stable/c/87c6efc5ce9c126ae4a781bc04504b83780e3650"}],"title":"net/sched: ets: use old 'nbands' while purging unused classes","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2025-38684","datePublished":"2025-09-04T15:32:38.927Z","dateReserved":"2025-04-16T04:51:24.032Z","dateUpdated":"2026-05-12T12:05:24.841Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2025-09-04 16:15:36","lastModifiedDate":"2026-05-12 13:16:54","problem_types":["CWE-476"],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":3.6}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.296","versionEndExcluding":"5.5","matchCriteriaId":"CB7B681B-677D-43AE-A21C-20F711958F8D"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"5.10.241","matchCriteriaId":"A99EBC77-F2BC-4614-93F8-3C332AAD980E"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.15.190","matchCriteriaId":"AD9E597F-3DDE-4D7E-976C-463D0611F13F"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.1.149","matchCriteriaId":"FDBE8280-8983-4D2D-943D-2E6D0104E2D8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.103","matchCriteriaId":"F2293654-7169-49B5-8D0D-EE51EF8B8E48"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.12.43","matchCriteriaId":"472C5F87-2BF3-4FAB-9B21-DA7513977363"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.15.11","matchCriteriaId":"BC242347-F722-43AE-B910-BE0B22386977"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.16.2","matchCriteriaId":"BD7C087D-2415-4521-B624-30003352F899"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*","matchCriteriaId":"327D22EF-390B-454C-BD31-2ED23C998A1C"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*","matchCriteriaId":"FA6FEEC2-9F11-4643-8827-749718254FED"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2025","CveId":"38684","Ordinal":"1","Title":"net/sched: ets: use old 'nbands' while purging unused classes","CVE":"CVE-2025-38684","Year":"2025"},"notes":[{"CveYear":"2025","CveId":"38684","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: ets: use old 'nbands' while purging unused classes\n\nShuang reported sch_ets test-case [1] crashing in ets_class_qlen_notify()\nafter recent changes from Lion [2]. The problem is: in ets_qdisc_change()\nwe purge unused DWRR queues; the value of 'q->nbands' is the new one, and\nthe cleanup should be done with the old one. The problem is here since my\nfirst attempts to fix ets_qdisc_change(), but it surfaced again after the\nrecent qdisc len accounting fixes. Fix it purging idle DWRR queues before\nassigning a new value of 'q->nbands', so that all purge operations find a\nconsistent configuration:\n\n - old 'q->nbands' because it's needed by ets_class_find()\n - old 'q->nstrict' because it's needed by ets_class_is_strict()\n\n BUG: kernel NULL pointer dereference, address: 0000000000000000\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n PGD 0 P4D 0\n Oops: Oops: 0000 [#1] SMP NOPTI\n CPU: 62 UID: 0 PID: 39457 Comm: tc Kdump: loaded Not tainted 6.12.0-116.el10.x86_64 #1 PREEMPT(voluntary)\n Hardware name: Dell Inc. PowerEdge R640/06DKY5, BIOS 2.12.2 07/09/2021\n RIP: 0010:__list_del_entry_valid_or_report+0x4/0x80\n Code: ff 4c 39 c7 0f 84 39 19 8e ff b8 01 00 00 00 c3 cc cc cc cc 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <48> 8b 17 48 8b 4f 08 48 85 d2 0f 84 56 19 8e ff 48 85 c9 0f 84 ab\n RSP: 0018:ffffba186009f400 EFLAGS: 00010202\n RAX: 00000000000000d6 RBX: 0000000000000000 RCX: 0000000000000004\n RDX: ffff9f0fa29b69c0 RSI: 0000000000000000 RDI: 0000000000000000\n RBP: ffffffffc12c2400 R08: 0000000000000008 R09: 0000000000000004\n R10: ffffffffffffffff R11: 0000000000000004 R12: 0000000000000000\n R13: ffff9f0f8cfe0000 R14: 0000000000100005 R15: 0000000000000000\n FS:  00007f2154f37480(0000) GS:ffff9f269c1c0000(0000) knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 0000000000000000 CR3: 00000001530be001 CR4: 00000000007726f0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n PKRU: 55555554\n Call Trace:\n  <TASK>\n  ets_class_qlen_notify+0x65/0x90 [sch_ets]\n  qdisc_tree_reduce_backlog+0x74/0x110\n  ets_qdisc_change+0x630/0xa40 [sch_ets]\n  __tc_modify_qdisc.constprop.0+0x216/0x7f0\n  tc_modify_qdisc+0x7c/0x120\n  rtnetlink_rcv_msg+0x145/0x3f0\n  netlink_rcv_skb+0x53/0x100\n  netlink_unicast+0x245/0x390\n  netlink_sendmsg+0x21b/0x470\n  ____sys_sendmsg+0x39d/0x3d0\n  ___sys_sendmsg+0x9a/0xe0\n  __sys_sendmsg+0x7a/0xd0\n  do_syscall_64+0x7d/0x160\n  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n RIP: 0033:0x7f2155114084\n Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d 25 f0 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89\n RSP: 002b:00007fff1fd7a988 EFLAGS: 00000202 ORIG_RAX: 000000000000002e\n RAX: ffffffffffffffda RBX: 0000560ec063e5e0 RCX: 00007f2155114084\n RDX: 0000000000000000 RSI: 00007fff1fd7a9f0 RDI: 0000000000000003\n RBP: 00007fff1fd7aa60 R08: 0000000000000010 R09: 000000000000003f\n R10: 0000560ee9b3a010 R11: 0000000000000202 R12: 00007fff1fd7aae0\n R13: 000000006891ccde R14: 0000560ec063e5e0 R15: 00007fff1fd7aad0\n  </TASK>\n\n [1] https://lore.kernel.org/netdev/e08c7f4a6882f260011909a868311c6e9b54f3e4.1639153474.git.dcaratti@redhat.com/\n [2] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com/","Type":"Description","Title":"net/sched: ets: use old 'nbands' while purging unused classes"}]}}}