CVSS 3.1
Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)
Атакува се
Време до експлоатация
Атакува се по мрежата, без особени условия, без вход и без действие от потребителя.
- Експлоатация: няма данни за експлоатация
- Атаката може да се автоматизира
Описание
Оригинално описание
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix UAF in async copy cancel and shutdown An async copy could be freed or used after free while a teardown caller (OFFLOAD_CANCEL, nfsd4_shutdown_copy, nfsd4_cancel_copy_by_sb) raced the copy kthread: - find_async_copy() bumped copy->refcount but left the copy on clp->async_copies, so the reaper's cleanup_async_copy() could run release_copy_files() concurrently with a cancel/shutdown caller. Both put and NULL nf_src/nf_dst without a common lock, double-putting the nfsd_file and freeing it early. - nfsd4_do_async_copy() set NFSD4_COPY_F_STOPPED before its final uses of the copy (nfsd_update_cmtime_attr() on copy->nf_dst, nfsd4_send_cb_offload()). nfsd4_stop_copy() treats a set STOPPED bit as "kthread done, skip kthread_stop()", so a teardown caller ran release_copy_files() -- which puts and NULLs nf_dst -- while the kthread still dereferenced it (NULL/UAF). - copy->copy_task was never pinned. The one-shot kthread self-reaps on return, so kthread_stop()'s get_task_struct() could touch a freed task_struct. - co_cb is embedded in the copy, but nfsd4_send_cb_offload() held a reference only on the client, so a concurrent teardown could free the copy while the CB_OFFLOAD callback was in flight. Fix the teardown lifetime as a whole: - find_async_copy() unlinks the copy (clear cp_clp, list_del_init) under async_lock; the cancel, shutdown, and sb-cancel paths drop the list-membership reference via nfs4_put_copy() after nfsd4_stop_copy(). Drop the now-redundant list_del fixup from cleanup_async_copy(). - Because unlinking hides the copy from the reaper, its cleanup_async_copy() can no longer remove the copy's s2s_cp_stateids entry; the cancel/shutdown/sb-cancel paths now call nfs4_free_copy_state() themselves (while cp_clp is still valid) so the entry does not dangle at freed memory for the laundromat and
Засегнати продукти
- Linux Linux: e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 преди 9031493ef7369d5c59c4bacc96f0c85965f09a98; e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 преди a385cf5e016b748babf94cc664e43a26e17db117; e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 преди 62c0f6eaf050bb9284c1f9cac6ed1770092e6b95
- Linux Linux: 4.20; преди 4.20; 6.18.51 до 6.18.*; 7.2.4 до 7.2.*; от 7.3 нататък
История
- 11 септември 2026 Публикувано
Други уязвимости в Linux Linux
Първоизточници
- https://www.cve.org/CVERecord?id=CVE-2026-89675
- https://nvd.nist.gov/vuln/detail/CVE-2026-89675
- https://git.kernel.org/stable/c/9031493ef7369d5c59c4bacc96f0c85965f09a98
- https://git.kernel.org/stable/c/a385cf5e016b748babf94cc664e43a26e17db117
- https://git.kernel.org/stable/c/62c0f6eaf050bb9284c1f9cac6ed1770092e6b95