CVE-2026-52923

A flaw was found in the Linux kernel. The ipc_idr_alloc() function, used in the checkpoint/restore path for SysV Inter-Process Communication (IPC) ID allocation, does not properly limit ID allocation to the valid range. This can result in the system attempting to dereference freed memory, leading to a use-after-free vulnerability. This issue could potentially cause system instability or information disclosure.

SysV IPC checkpoint restore next_id allocation can escape the valid IPC id range because ipc_idr_alloc used an open ended idr_alloc upper bound. A crafted local sequence can leave a shared memory object stored in an out of range IDR slot, while later removal truncates the encoded id and removes a different in range slot. This can leave a stale IDR pointer to freed shared memory state, and a later /proc/sysvipc/shm walk can dereference freed memory. Impact is local denial of service.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.