In the Linux kernel, the following vulnerability has been resolved:
perf sched: Fix register_pid() overflow, strcpy, and BUG_ON
register_pid() has several issues when processing untrusted perf.data:
1. Integer overflow: (pid + 1) * sizeof(struct task_desc *) can wrap
to a small value on 32-bit systems when pid is large (e.g.
0x40000000), causing realloc to return a tiny buffer followed by
out-of-bounds writes in the initialization loop.
2. Heap buffer overflow: strcpy(task->comm, comm) copies the
untrusted comm string into a fixed 20-byte COMM_LEN buffer with
no length check.
3. BUG_ON on allocation failure: perf.data is untrusted input, so
allocation failures should be handled gracefully rather than
killing the process.
4. Realloc of sched->tasks assigned directly back, leaking the old
pointer on failure; nr_tasks incremented before the realloc,
leaving corrupted state on failure.
Cap pid at PID_MAX_LIMIT (4194304, matching the kernel's maximum
on 64-bit), replace strcpy with strlcpy, guard against NULL comm,
replace BUG_ON with NULL returns using safe realloc patterns, and
add NULL checks in callers that dereference the result.
perf sched: Fix register_pid() overflow, strcpy, and BUG_ON
register_pid() has several issues when processing untrusted perf.data:
1. Integer overflow: (pid + 1) * sizeof(struct task_desc *) can wrap
to a small value on 32-bit systems when pid is large (e.g.
0x40000000), causing realloc to return a tiny buffer followed by
out-of-bounds writes in the initialization loop.
2. Heap buffer overflow: strcpy(task->comm, comm) copies the
untrusted comm string into a fixed 20-byte COMM_LEN buffer with
no length check.
3. BUG_ON on allocation failure: perf.data is untrusted input, so
allocation failures should be handled gracefully rather than
killing the process.
4. Realloc of sched->tasks assigned directly back, leaking the old
pointer on failure; nr_tasks incremented before the realloc,
leaving corrupted state on failure.
Cap pid at PID_MAX_LIMIT (4194304, matching the kernel's maximum
on 64-bit), replace strcpy with strlcpy, guard against NULL comm,
replace BUG_ON with NULL returns using safe realloc patterns, and
add NULL checks in callers that dereference the result.
Metrics
Affected Vendors & Products
Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 28 Aug 2026 07:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: perf sched: Fix register_pid() overflow, strcpy, and BUG_ON register_pid() has several issues when processing untrusted perf.data: 1. Integer overflow: (pid + 1) * sizeof(struct task_desc *) can wrap to a small value on 32-bit systems when pid is large (e.g. 0x40000000), causing realloc to return a tiny buffer followed by out-of-bounds writes in the initialization loop. 2. Heap buffer overflow: strcpy(task->comm, comm) copies the untrusted comm string into a fixed 20-byte COMM_LEN buffer with no length check. 3. BUG_ON on allocation failure: perf.data is untrusted input, so allocation failures should be handled gracefully rather than killing the process. 4. Realloc of sched->tasks assigned directly back, leaking the old pointer on failure; nr_tasks incremented before the realloc, leaving corrupted state on failure. Cap pid at PID_MAX_LIMIT (4194304, matching the kernel's maximum on 64-bit), replace strcpy with strlcpy, guard against NULL comm, replace BUG_ON with NULL returns using safe realloc patterns, and add NULL checks in callers that dereference the result. | |
| Title | perf sched: Fix register_pid() overflow, strcpy, and BUG_ON | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-28T06:49:11.744Z
Reserved: 2026-08-26T14:34:25.782Z
Link: CVE-2026-80671
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-08-28T08:16:52.410
Modified: 2026-08-28T08:16:52.410
Link: CVE-2026-80671
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.