CVE-2026-52923

In the Linux kernel, the following vulnerability has been resolved: ipc: limit next_id allocation to the valid ID range The checkpoint/restore sysctl path can request the next SysV IPC id through ids->next_id. ipc_idr_alloc() currently forwards that request to idr_alloc() with an open-ended upper bound. If the valid tail of the SysV IPC id space is full, the allocation can spill beyond ipc_mni. The returned SysV IPC id still uses the normal index encoding, so later lookup and removal can target the wrong slot. This leaves the real IDR entry behind and breaks the IDR state for the object. The bug is in ipc_idr_alloc() in the checkpoint/restore path. 1. ids->next_id is passed to: idr_alloc(&ids->ipcs_idr, new, ipcid_to_idx(next_id), 0, ...) 2. The zero upper bound makes the allocation effectively open-ended. Once the valid SysV IPC tail is occupied, idr_alloc() can spill past ipc_mni and allocate an entry beyond the valid IPC id range. 3. The new object id is still encoded with the narrower SysV IPC index width: new->id = (new->seq << ipcmni_seq_shift()) + idx 4. Later removal goes through ipc_rmid(), which uses: ipcid_to_idx(ipcp->id) That truncates the real IDR index. An object actually stored at a high index can then be removed as if it lived at a low in-range index. 5. For shared memory, shm_destroy() frees the current object anyway, but the real high IDR slot is left behind as a dangling pointer. 6. A subsequent walk of /proc/sysvipc/shm reaches the stale IDR entry and dereferences freed memory. Prevent this by bounding the requested allocation to ipc_mni so the checkpoint/restore path fails once the valid range is exhausted.
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.8:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.8:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.8:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.8:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.8:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.8:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*

History

08 Jul 2026, 15:29

Type Values Removed Values Added
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.8:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.8:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.8:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.8:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.8:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.8:rc3:*:*:*:*:*:*
CWE CWE-401
First Time Linux linux Kernel
Linux
References () https://git.kernel.org/stable/c/157ce2c6836ce0ff19108a819f38df061345425f - () https://git.kernel.org/stable/c/157ce2c6836ce0ff19108a819f38df061345425f - Patch
References () https://git.kernel.org/stable/c/3bbe2bb9111ce6967a951bfac79af142d816fae5 - () https://git.kernel.org/stable/c/3bbe2bb9111ce6967a951bfac79af142d816fae5 - Patch
References () https://git.kernel.org/stable/c/41058d4c3f63ab64901560a704882e0565f4e456 - () https://git.kernel.org/stable/c/41058d4c3f63ab64901560a704882e0565f4e456 - Patch
References () https://git.kernel.org/stable/c/8c58a92849175f5e2ab7bc2734b3b89afe79f6ef - () https://git.kernel.org/stable/c/8c58a92849175f5e2ab7bc2734b3b89afe79f6ef - Patch
References () https://git.kernel.org/stable/c/a3cc795129e5ec0f8948653a3bf471e7d8852f5e - () https://git.kernel.org/stable/c/a3cc795129e5ec0f8948653a3bf471e7d8852f5e - Patch
References () https://git.kernel.org/stable/c/af24e202b543ded8a34f1d5d3db54eb916173f04 - () https://git.kernel.org/stable/c/af24e202b543ded8a34f1d5d3db54eb916173f04 - Patch
References () https://git.kernel.org/stable/c/bd4be70669af55b974860d13680348cfdf50bbed - () https://git.kernel.org/stable/c/bd4be70669af55b974860d13680348cfdf50bbed - Patch
References () https://git.kernel.org/stable/c/fa0b9b2b7ae3539908d69c2b9ac0d144d9bc5139 - () https://git.kernel.org/stable/c/fa0b9b2b7ae3539908d69c2b9ac0d144d9bc5139 - Patch
References () https://access.redhat.com/security/cve/CVE-2026-52923 - () https://access.redhat.com/security/cve/CVE-2026-52923 - Third Party Advisory
References () https://bugzilla.redhat.com/show_bug.cgi?id=2492094 - () https://bugzilla.redhat.com/show_bug.cgi?id=2492094 - Issue Tracking, Third Party Advisory
References () https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52923.json - () https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52923.json - Third Party Advisory

30 Jun 2026, 03:20

Type Values Removed Values Added
CWE CWE-825
References
  • () https://access.redhat.com/security/cve/CVE-2026-52923 -
  • () https://bugzilla.redhat.com/show_bug.cgi?id=2492094 -
  • () https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52923.json -

28 Jun 2026, 08:16

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.8

24 Jun 2026, 08:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-06-24 08:16

Updated : 2026-07-15 01:16


NVD link : CVE-2026-52923

Mitre link : CVE-2026-52923

CVE.ORG link : CVE-2026-52923


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-401

Missing Release of Memory after Effective Lifetime

CWE-825

Expired Pointer Dereference