CVE-2026-52930 ipc/shm: serialize orphan cleanup with shm_nattch updates

In the Linux kernel, the following vulnerability has been resolved: ipc/shm: serialize orphan cleanup with shmnattch updates shmdestroyorphaned walks the shm idr under shmidsns.rwsem, but that does not serialize all fields tested by shmmaydestroy. In particular, shmnattch is updated while holding...

CVE-2026-52930

CVE-2026-52930 (Linux kernel) : The issue is in ipc/shm: orphan cleanup cleanup of shm segments. shm_nattch was updated while holding shm_perm.lock, but shm_destroy_orphaned() traversed shm_ids(ns).rwsem, leading to a race where an orphaned segment could be considered removable before the destina...