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Оригинално описание
In the Linux kernel, the following vulnerability has been resolved: net/sched: account classifier filter allocations to memcg Allocations in the tc classifier *_change() paths (filter objects, per-CPU counters, and per-filter aux data) use plain GFP_KERNEL without __GFP_ACCOUNT, allowing unprivileged users to pin kernel memory outside memcg charging. The shared tcf_exts_init_ex() action array allocation in cls_api.c was also uncharged; this patch closes it along with the per-classifier filter-object/percpu/aux allocations that remain unaccounted. Add GFP_KERNEL_ACCOUNT to: - the shared tcf_exts_init_ex() action array (cls_api.c), common to every filter of every classifier (32 pointers, 256 bytes); - the filter-object, per-CPU-counter, and per-filter aux allocations in cls_basic, cls_bpf, cls_cgroup, cls_flow, cls_flower, cls_fw, cls_matchall, cls_route and cls_u32; - the u32_init_knode() replace-path knode allocation (cls_u32.c), which allocates the same struct tc_u_knode + sel.keys on every replace of an existing knode and was missed by the create-path-only conversion. Also fix the cls_basic error path: basic_change() inserts fnew into the IDR before allocating the per-CPU counter. If alloc_percpu() fails the errout path kfree'd fnew without idr_remove, leaving a dangling pointer in the IDR. With GFP_KERNEL_ACCOUNT the percpu alloc becomes failable on demand (memcg at memory.max), making the dead path attacker-reachable and burning the handle permanently. Add the idr_remove on the percpu failure path, matching the basic_set_parms failure-path pattern. Note: [email protected] provided a poc for basic_cls, but it was easy to extend to the other classifiers. Conditions to recreate the bug: - CONFIG_NET_SCHED, CONFIG_NET_CLS_* (the classifier being used), CONFIG_NET_CLS_ACT, CONFIG_MEMCG, CONFIG_USER_NS, CONFIG_NET_NS. - Unprivileged user in a fresh user+network namespace (unshare -Urn), or root with CAP_NET_ADMIN. - Create a large number of tc filter
Засегнати продукти
- Linux Linux: 0da974f4f303a6842516b764507e3c0a03f41e5a преди 8a622d5b4d81c1572f42bbf3fb823b6e63d44dae; 0da974f4f303a6842516b764507e3c0a03f41e5a преди 5fbb06d4f3d4c509ffe95572384a498bf319e5bf; 0da974f4f303a6842516b764507e3c0a03f41e5a преди bf6006cea193cf065f7a64fc7974247f8112af33; 0da974f4f303a6842516b764507e3c0a03f41e5a преди 68fb30607169c92de57c5c82b6af8a733af1cc09; 0da974f4f303a6842516b764507e3c0a03f41e5a преди 18c68c8f3d3ff0a4def1391021b439c4333a6c71; 0da974f4f303a6842516b764507e3c0a03f41e5a преди 1beb81947eb486716af80db7a584f9e9fef7e003
- Linux Linux: 2.6.18; преди 2.6.18; 6.1.191 до 6.1.*; 6.6.160 до 6.6.*; 6.12.114 до 6.12.*; 6.18.57 до 6.18.*; 7.2.6 до 7.2.*; 7.3 до *
История
- 17 септември 2026 Публикувано
Други уязвимости в Linux Linux
Първоизточници
- https://www.cve.org/CVERecord?id=CVE-2026-90099
- https://nvd.nist.gov/vuln/detail/CVE-2026-90099
- https://git.kernel.org/stable/c/8a622d5b4d81c1572f42bbf3fb823b6e63d44dae
- https://git.kernel.org/stable/c/5fbb06d4f3d4c509ffe95572384a498bf319e5bf
- https://git.kernel.org/stable/c/bf6006cea193cf065f7a64fc7974247f8112af33
- https://git.kernel.org/stable/c/68fb30607169c92de57c5c82b6af8a733af1cc09
- https://git.kernel.org/stable/c/18c68c8f3d3ff0a4def1391021b439c4333a6c71
- https://git.kernel.org/stable/c/1beb81947eb486716af80db7a584f9e9fef7e003