When semop(2) blocks waiting for a semaphore condition, it releases the per-set lock and sleeps. Upon waking, it checks the sequence number embedded in the semaphore set's IPC identifier to detect whether the set was removed while the caller was asleep. This sequence number is only 15 bits wide. If enough semaphore sets are created and destroyed in the same table slot while a caller is blocked, the counter wraps around, and semop(2) may falsely conclude that the original set still exists. The subsequent access to a semaphore within the set may then be out of bounds.
An unprivileged local user can trigger an out-of-bounds access on kernel heap memory, potentially leading to privilege escalation.
An unprivileged local user can trigger an out-of-bounds access on kernel heap memory, potentially leading to privilege escalation.
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Fixes
Solution
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Workaround
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References
History
Thu, 15 Oct 2026 06:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | When semop(2) blocks waiting for a semaphore condition, it releases the per-set lock and sleeps. Upon waking, it checks the sequence number embedded in the semaphore set's IPC identifier to detect whether the set was removed while the caller was asleep. This sequence number is only 15 bits wide. If enough semaphore sets are created and destroyed in the same table slot while a caller is blocked, the counter wraps around, and semop(2) may falsely conclude that the original set still exists. The subsequent access to a semaphore within the set may then be out of bounds. An unprivileged local user can trigger an out-of-bounds access on kernel heap memory, potentially leading to privilege escalation. | |
| Title | Heap out-of-bounds access in semop(2) | |
| Weaknesses | CWE-787 | |
| References |
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Status: PUBLISHED
Assigner: freebsd
Published:
Updated: 2026-10-15T06:15:44.878Z
Reserved: 2026-06-29T01:40:17.499Z
Link: CVE-2026-58098
No data.
Status : Awaiting Analysis
Published: 2026-10-15T07:18:02.250
Modified: 2026-10-15T16:17:41.437
Link: CVE-2026-58098
No data.
OpenCVE Enrichment
Updated: 2026-10-15T11:30:18Z
Weaknesses