CVE-2026-52923
published 2026-06-24CVE-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…
PriorityP340high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.13%
2.7th percentile
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 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.
Affected
28 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | >= 03f595668017f1a1fb971c02fc37140bc6e7bb1c < 3bbe2bb9111ce6967a951bfac79af142d816fae5 | 3bbe2bb9111ce6967a951bfac79af142d816fae5 |
| linux | linux | >= 03f595668017f1a1fb971c02fc37140bc6e7bb1c < 8c58a92849175f5e2ab7bc2734b3b89afe79f6ef | 8c58a92849175f5e2ab7bc2734b3b89afe79f6ef |
| linux | linux | >= 03f595668017f1a1fb971c02fc37140bc6e7bb1c < af24e202b543ded8a34f1d5d3db54eb916173f04 | af24e202b543ded8a34f1d5d3db54eb916173f04 |
| linux | linux | >= 03f595668017f1a1fb971c02fc37140bc6e7bb1c < 157ce2c6836ce0ff19108a819f38df061345425f | 157ce2c6836ce0ff19108a819f38df061345425f |
| linux | linux | >= 03f595668017f1a1fb971c02fc37140bc6e7bb1c < 41058d4c3f63ab64901560a704882e0565f4e456 | 41058d4c3f63ab64901560a704882e0565f4e456 |
| linux | linux | >= 03f595668017f1a1fb971c02fc37140bc6e7bb1c < a3cc795129e5ec0f8948653a3bf471e7d8852f5e | a3cc795129e5ec0f8948653a3bf471e7d8852f5e |
| linux | linux | >= 03f595668017f1a1fb971c02fc37140bc6e7bb1c < bd4be70669af55b974860d13680348cfdf50bbed | bd4be70669af55b974860d13680348cfdf50bbed |
| linux | linux | >= 03f595668017f1a1fb971c02fc37140bc6e7bb1c < fa0b9b2b7ae3539908d69c2b9ac0d144d9bc5139 | fa0b9b2b7ae3539908d69c2b9ac0d144d9bc5139 |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 3.8.1 < 5.10.259 | 5.10.259 |
| linux | linux_kernel | >= 5.11 < 5.15.210 | 5.15.210 |
| linux | linux_kernel | >= 5.16 < 6.1.176 | 6.1.176 |
| linux | linux_kernel | >= 6.13 < 6.18.35 | 6.18.35 |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vendor_redhat7.0HIGH
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Red Hat
kernel: ipc: limit next_id allocation to the valid ID range
vendor_redhat·2026-06-24·CVSS 7.0
CVE-2026-52923 [HIGH] CWE-825 kernel: ipc: limit next_id allocation to the valid ID range
kernel: ipc: limit next_id allocation to the valid ID range
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.
Package: kernel (Red Hat Enterprise Linux 10) - Affected
Package: kernel (Red Hat Enterprise Linux 6) - Under investigation
Package: kernel (Red Hat Enterprise Linux 7) - Affected
Package: kernel-rt (Red Hat Enterprise Linux 7) - Affected
Package: kernel (Red Hat Enterprise Linux 8) - Affected
Package: kernel-rt (Re
GHSA
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 id
ghsa_unreviewed·2026-06-24
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 id
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
No detection rules found.
No public exploits indexed.
https://git.kernel.org/stable/c/157ce2c6836ce0ff19108a819f38df061345425fhttps://git.kernel.org/stable/c/3bbe2bb9111ce6967a951bfac79af142d816fae5https://git.kernel.org/stable/c/41058d4c3f63ab64901560a704882e0565f4e456https://git.kernel.org/stable/c/8c58a92849175f5e2ab7bc2734b3b89afe79f6efhttps://git.kernel.org/stable/c/a3cc795129e5ec0f8948653a3bf471e7d8852f5ehttps://git.kernel.org/stable/c/af24e202b543ded8a34f1d5d3db54eb916173f04https://git.kernel.org/stable/c/bd4be70669af55b974860d13680348cfdf50bbedhttps://git.kernel.org/stable/c/fa0b9b2b7ae3539908d69c2b9ac0d144d9bc5139https://access.redhat.com/security/cve/CVE-2026-52923https://bugzilla.redhat.com/show_bug.cgi?id=2492094https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52923.json
2026-06-24
Published