net/sched: teql: Fix double-free in teql_master_xmit_CVE-2026-23449

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: teql: Fix double-free in teql_master_xmit\n\nWhenever a TEQL devices has a lockless Qdisc as root, qdisc_reset should\nbe called using the seq_lock to avoid racing with the datapath. Failure\nto do so may cause crashes like the following:\n\n[  238.028993][  T318] BUG: KASAN: double-free in skb_release_data (net/core/skbuff.c:1139)\n[  238.029328][  T318] Free of addr ffff88810c67ec00 by task poc_teql_uaf_ke/318\n[  238.029749][  T318]\n[  238.029900][  T318] CPU: 3 UID: 0 PID: 318 Comm: poc_teql_ke Not tainted 7.0.0-rc3-00149-ge5b31d988a41 #704 PREEMPT(full)\n[  238.029906][  T318] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011\n[  238.029910][  T318] Call Trace:\n[  238.029913][  T318]  <TASK>\n[  238.029916][  T318]  dump_stack_lvl (lib/dump_stack.c:122)\n[  238.029928][  T318]  print_report (mm/kasan/report.c:379 mm/kasan/report.c:482)\n[  238.029940][  T318]  ? skb_release_data (net/core/skbuff.c:1139)\n[  238.029944][  T318]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)\n...\n[  238.029957][  T318]  ? skb_release_data (net/core/skbuff.c:1139)\n[  238.029969][  T318]  kasan_report_invalid_free (mm/kasan/report.c:221 mm/kasan/report.c:563)\n[  238.029979][  T318]  ? skb_release_data (net/core/skbuff.c:1139)\n[  238.029989][  T318]  check_slab_allocation (mm/kasan/common.c:231)\n[  238.029995][  T318]  kmem_cache_free (mm/slub.c:2637 (discriminator 1) mm/slub.c:6168 (discriminator 1) mm/slub.c:6298 (discriminator 1))\n[  238.030004][  T318]  skb_release_data (net/core/skbuff.c:1139)\n...\n[  238.030025][  T318]  sk_skb_reason_drop (net/core/skbuff.c:1256)\n[  238.030032][  T318]  pfifo_fast_reset (./include/linux/ptr_ring.h:171 ./include/linux/ptr_ring.h:309 ./include/linux/skb_array.h:98 net/sched/sch_generic.c:827)\n[  238.030039][  T318]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)\n...\n[  238.030054][  T318]  qdisc_reset (net/sched/sch_generic.c:1034)\n[  238.030062][  T318]  teql_destroy (./include/linux/spinlock.h:395 net/sched/sch_teql.c:157)\n[  238.030071][  T318]  __qdisc_destroy (./include/net/pkt_sched.h:328 net/sched/sch_generic.c:1077)\n[  238.030077][  T318]  qdisc_graft (net/sched/sch_api.c:1062 net/sched/sch_api.c:1053 net/sched/sch_api.c:1159)\n[  238.030089][  T318]  ? __pfx_qdisc_graft (net/sched/sch_api.c:1091)\n[  238.030095][  T318]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)\n[  238.030102][  T318]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)\n[  238.030106][  T318]  ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)\n[  238.030114][  T318]  tc_get_qdisc (net/sched/sch_api.c:1529 net/sched/sch_api.c:1556)\n...\n[  238.072958][  T318] Allocated by task 303 on cpu 5 at 238.026275s:\n[  238.073392][  T318]  kasan_save_stack (mm/kasan/common.c:58)\n[  238.073884][  T318]  kasan_save_track (mm/kasan/common.c:64 (discriminator 5) mm/kasan/common.c:79 (discriminator 5))\n[  238.074230][  T318]  __kasan_slab_alloc (mm/kasan/common.c:369)\n[  238.074578][  T318]  kmem_cache_alloc_node_noprof (./include/linux/kasan.h:253 mm/slub.c:4542 mm/slub.c:4869 mm/slub.c:4921)\n[  238.076091][  T318]  kmalloc_reserve (net/core/skbuff.c:616 (discriminator 107))\n[  238.076450][  T318]  __alloc_skb (net/core/skbuff.c:713)\n[  238.076834][  T318]  alloc_skb_with_frags (./include/linux/skbuff.h:1383 net/core/skbuff.c:6763)\n[  238.077178][  T318]  sock_alloc_send_pskb (net/core/sock.c:2997)\n[  238.077520][  T318]  packet_sendmsg (net/packet/af_packet.c:2926 net/packet/af_packet.c:3019 net/packet/af_packet.c:3108)\n[  238.081469][  T318]\n[  238.081870][  T318] Freed by task 299 on cpu 1 at 238.028496s:\n[  238.082761][  T318]  kasan_save_stack (mm/kasan/common.c:58)\n[  238.083481][  T318]  kasan_save_track (mm/kasan/common.c:64 (discriminator 5) mm/kasan/common.c:79 (discriminator 5))\n[  238.085348][  T318]  kasan_save_free_info (mm/kasan/generic.c:587 (discriminator 1))\n[  238.085900][  T318]  __kasan_slab_free (mm/\n---truncated---",
    "published": "2026-04-03T15:15:32.150Z",
    "modified": "2026-04-27T14:02:28.557Z",
    "type": "cve",
    "title": "net/sched: teql: Fix double-free in teql_master_xmit",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/4e8ebc4c18ea8213d28e6cb867d18fcc67daca21\nhttps://git.kernel.org/stable/c/21c89a0a8de7eadad8d385645a95b3233f23130e\nhttps://git.kernel.org/stable/c/afbc79a7770b230a9f24bd39271209d6b3682c5f\nhttps://git.kernel.org/stable/c/e9c66d3e7d8557b3308e55c613aa07254fe97611\nhttps://git.kernel.org/stable/c/4a233447b941db451ea5f5a0942cffd0f7f7eaae\nhttps://git.kernel.org/stable/c/66360460cab63c248ca5b1070a01c0c29133b960",
    "id": "CVE-2026-23449",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux 96009c7d500efdd5534e83b2e3eb2c58d4b137ae\nLinux Linux 96009c7d500efdd5534e83b2e3eb2c58d4b137ae\nLinux Linux 96009c7d500efdd5534e83b2e3eb2c58d4b137ae\nLinux Linux 96009c7d500efdd5534e83b2e3eb2c58d4b137ae\nLinux Linux 96009c7d500efdd5534e83b2e3eb2c58d4b137ae\nLinux Linux 96009c7d500efdd5534e83b2e3eb2c58d4b137ae\nLinux Linux 4.18",
    "sourceHref": "",
    "cvss": {
        "score": 7.8,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "96009c7d500efdd5534e83b2e3eb2c58d4b137ae",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}