CVE-2026-98813

Что произошло

In the Linux kernel, the following vulnerability has been resolved: bpf: Hold map BTF for the memory allocator destructor record bpf_ma_set_dtor() duplicates map->record so that the bpf_mem_alloc destructor can release the special fields of hash and rhash map elements once the allocator frees them for good. btf_record_dup() only acquires references on kernel and module BTF. Fields whose types live in the map BTF keep pointing into it: a kptr to a local type refers to map->btf, and a list_head or rb_root field carries a value_rec owned by the struct meta table of map->btf. That borrowed state can outlive the map. When RCU callbacks are still in flight, bpf_mem_alloc_destroy() copies the allocator and defers the final drain, together with the destructor context, to a workqueue. bpf_map_free() then frees map->record and drops the map's BTF reference as soon as map_free() returns. Once the program that loaded the BTF is gone as well, the BTF is freed while the worker still uses the duplicate. The worker dereferences it through btf_is_kernel() and btf_find_struct_meta() in bpf_obj_free_fields() when destroying elements that were freed under RCU, and through btf_is_kernel() in btf_record_free() when releasing the context itself: BUG: KASAN: slab-use-after-free in btf_is_kernel+0x19/0x30 Read of size 1 at addr ffff88811505dce8 by task kworker/u16:2/50 Workqueue: events_unbound free_mem_alloc_deferred Call Trace: btf_is_kernel+0x19/0x30 btf_record_free+0xc7/0xf0 htab_dtor_ctx_free+0x1a/0x30 free_mem_alloc_no_barrier+0x39/0x230 free_mem_alloc_deferred+0x2a/0x40 process_scheduled_works+0x5ce/0x9d0 worker_thread+0x42a/0x5e0 kthread+0x1f5/0x230 ret_from_fork+0x1dd/0x390 ret_from_fork_asm+0x1a/0x30 Allocated by task 358: __kmalloc_cache_noprof+0x287/0x510 btf_new_fd+0xf7/0x3d0 __sys_bpf+0x487/0x840 Freed by task 0: kfree+0x186/0x560 rcu_core+0x6f6/0xd40 Freeing a map that still holds more elements than the allocator's high watermark is enough to get there, because the bulk free during teardown queues the RCU callback that makes bpf_mem_alloc_destroy() defer. Non-preallocated hash maps and resizable hash maps both register the destructor and are affected alike. Keep one reference on the map BTF in the destructor context. Every non-kernel pointer in the duplicated record is either map->btf or memory owned by it, so a single reference covers kptrs, list heads, and rb roots, and mirrors what bpf_map_meta_alloc() does for the duplicated record of an inner map. Release it only after the duplicated record has been freed: the worker is preemptible and not in an RCU read-side critical section, so dropping the last reference first would let the BTF be freed while btf_record_free() still reads its fields.

Что делать

dpkg-query -W -f='${Package}	${Version}\n'

rpm -qa --qf '%{NAME}\t%{VERSION}-%{RELEASE}\n'

Get-HotFix | Select-Object HotFixID, InstalledOn

Продукты и затронутые версии

{
  "status": "affected",
  "version": "1df97a7453eec80c1912c2d0360290a3970a7671",
  "lessThan": "b506f5699e145196ee29d76cf1ca1cbb2202c055",
  "versionType": "git"
}

{
  "status": "affected",
  "version": "1df97a7453eec80c1912c2d0360290a3970a7671",
  "lessThan": "ab39974240a0cff765f3bb9cce81d8001ffdb144",
  "versionType": "git"
}

{
  "status": "affected",
  "version": "451a84a3ad3c897c03181af433e7c98640730f1f",
  "versionType": "git"
}

{
  "status": "affected",
  "version": "51a17f0ce19c4ee2a25cf16c93490d509b1ebb0a",
  "versionType": "git"
}

{
  "status": "affected",
  "version": "6.12.112",
  "lessThan": "6.13",
  "versionType": "semver"
}

{
  "status": "affected",
  "version": "6.18.55",
  "lessThan": "6.19",
  "versionType": "semver"
}

{
  "status": "affected",
  "version": "7.0"
}

{
  "status": "unaffected",
  "version": "0",
  "lessThan": "7.0",
  "versionType": "semver"
}

{
  "status": "unaffected",
  "version": "7.2.10",
  "versionType": "semver",
  "lessThanOrEqual": "7.2.*"
}

{
  "status": "unaffected",
  "version": "7.3",
  "versionType": "original_commit_for_fix",
  "lessThanOrEqual": "*"
}

CVSS: оценки и векторы

Оценка CVSS отсутствует.

Источники и ссылки

{
  "cwes": [],
  "epss": {
    "source": "epss",
    "received_at": "2026-11-02T21:15:49.062475+00:00"
  },
  "title": {
    "source": "cve",
    "received_at": "2026-10-28T20:15:08.438618+00:00"
  },
  "scores": [],
  "status": {
    "source": "cve",
    "received_at": "2026-10-28T20:15:08.438618+00:00"
  },
  "affected": [
    "cve"
  ],
  "published": {
    "source": "cve",
    "received_at": "2026-10-28T20:15:08.438618+00:00"
  },
  "solutions": [],
  "percentile": {
    "source": "epss",
    "received_at": "2026-11-02T21:15:49.062475+00:00"
  },
  "references": [
    "cve"
  ],
  "description": {
    "source": "cve",
    "received_at": "2026-10-28T20:15:08.438618+00:00"
  },
  "workarounds": [],
  "configurations": []
}

Хронология записи

1. Данные обновлены03.11.2026, 00:15
2. Данные обновлены02.11.2026, 00:13
3. Данные обновлены31.10.2026, 12:00
4. Данные обновлены29.10.2026, 12:47
5. Опубликована28.10.2026, 23:15

Личная заметка и статус

Другие CVE того же продукта