#CVE-2026-99224

NVD の情報

In the Linux kernel, the following vulnerability has been resolved: keys: Protect the type name while describing a key keyctl_describe_key() must keep the key type's name alive until kasprintf() has consumed it. The retained key reference keeps the key and its description alive, but does not pin the module providing its type. The name is passed to kasprintf() without holding key->sem. kvasprintf() uses the saved name pointer in two formatting passes, with a GFP_KERNEL allocation between them. With AF_RXRPC=m, a task that passes View permission before type retirement can overlap a privileged module unload in this order: 1. KEYCTL_DESCRIBE looks up the key, saves key->type->name in the kasprintf() arguments and completes the first formatting pass. 2. While the formatter is delayed before its second pass, af_rxrpc_exit() calls unregister_key_type(), which removes the type from the registry and waits for key_gc_keytype(). 3. The collector takes key->sem for writing, retypes the retained key to key_type_dead and completes retirement. Unregistration and module exit return, allowing free_module() to release the type and name. 4. The formatter resumes its second pass and reads the saved name from released module storage, which can fault in string(). Hold key->sem for reading across kasprintf(). The collector then cannot retype the key or complete retirement until both formatting passes have finished. If retirement wins the lock first, formatting uses the core key_type_dead name instead. Release the semaphore immediately after kasprintf(), including on allocation failure, before copying to userspace. Oops report as below: BUG: unable to handle page fault for address: fffffbfff8054794 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:string+0x23f/0x470 Call Trace: vsnprintf+0x330/0x1110

公開日

2026-11-02

最終更新（NVD）

2026-11-03

NVD の状態

Received

深刻度（CVSS）

• 7.0 HighCVSS 3.1／副／評価：416baaa9-dc9f-4396-8d5f-8c081fb06d67CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

悪用の状況

CISA KEV には掲載されていません（掲載されていないことは、悪用されていないことの証明ではありません）。

EPSS：今後30日に悪用される推定確率 0.12%（全体の上位 98.2%、評価日 2026-11-04）

解消方法

• 解消方法の情報なし

「NVD の条件から推定」は、NVD が影響ありとする版の上限から読み取ったもので、修正版とは限りません。「解消方法の情報なし」は、修正が無いという意味ではありません。必ずベンダーの公告で確認してください。

編集部の記載（レポート掲載時）

レポートの編集部がベンダー公告などから転記した内容です。検証済みの値ではないため、必ず出典で確認してください。

参照（NVD）

• https://git.kernel.org/stable/c/0461bc8f91116aae4a020e15f4e1c1fd535ab35e
• https://git.kernel.org/stable/c/19c4de819e52b7f606468fbfe4fcef4e812e2777
• https://git.kernel.org/stable/c/3c3cfd9e262afc9558c38f8cec57f09d10988546
• https://git.kernel.org/stable/c/6b613747f7ea309ada5b8d05b55398c338f7a968
• https://git.kernel.org/stable/c/916667df7695366f23cfaf365b5840b228cc4b2e
• https://git.kernel.org/stable/c/a49e6c9a1a5b3457c946a8efb616ce13b4ca8194
• https://git.kernel.org/stable/c/dddd3a1ab7d12ee163477918ff6eb943361db4fe
• https://git.kernel.org/stable/c/dea367df18e3a4faac393e3a4e818ee03af89b19
• https://git.kernel.org/stable/c/fced7238b7e80cf8aa688d5af976e4aa6e33c329