ipc: limit next_id allocation to the valid ID range
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 der
CVE-2026-52923
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-52923
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "03f595668017f1a1fb971c02fc37140bc6e7bb1c",
"lessThan": "3bbe2bb9111ce6967a951bfac79af142d816fae5",
"versionType": "git"
},
{
"status": "affected",
"version": "03f595668017f1a1fb971c02fc37140bc6e7bb1c",
"lessThan": "8c58a92849175f5e2ab7bc2734b3b89afe79f6ef",
"versionType": "git"
},
{
"status": "affected",
"version": "03f595668017f1a1fb971c02fc37140bc6e7bb1c",
"lessThan": "af24e202b543ded8a34f1d5d3db54eb916173f04",
"versionType": "git"
},
{
"status": "affected",
"version": "03f595668017f1a1fb971c02fc37140bc6e7bb1c",
"lessThan": "157ce2c6836ce0ff19108a819f38df061345425f",
"versionType": "git"
},
{
"status": "affected",
"version": "03f595668017f1a1fb971c02fc37140bc6e7bb1c",
"lessThan": "41058d4c3f63ab64901560a704882e0565f4e456",
"versionType": "git"
},
{
"status": "affected",
"version": "03f595668017f1a1fb971c02fc37140bc6e7bb1c",
"lessThan": "a3cc795129e5ec0f8948653a3bf471e7d8852f5e",
"versionType": "git"
},
{
"status": "affected",
"version": "03f595668017f1a1fb971c02fc37140bc6e7bb1c",
"lessThan": "bd4be70669af55b974860d13680348cfdf50bbed",
"versionType": "git"
},
{
"status": "affected",
"version": "03f595668017f1a1fb971c02fc37140bc6e7bb1c",
"lessThan": "fa0b9b2b7ae3539908d69c2b9ac0d144d9bc5139",
"versionType": "git"
}
],
"programFiles": [
"ipc/util.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.8"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.8",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.259",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.210",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.176",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.143",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.93",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.35",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.12",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"ipc/util.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-52923
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40696 · Revision 1
- Added to Heist Feed
- Publisher date