CVE-2026-97587
perf: RISC-V: store available counter mask as bitmap
Description
In the Linux kernel, the following vulnerability has been resolved: perf: RISC-V: store available counter mask as bitmap The available-counter mask was a single unsigned long, but iteration uses RISCV_MAX_COUNTERS, which is 64. On RV32 that reads past the object. Filling with an unsigned-long bit at index 32 and above is also wrong. Use DECLARE_BITMAP and set_bit/bitmap helpers. Walk each bitmap word into CFG_MATCH when checking events, when allocating an index, and when stopping all counters. Set the counter base to i times BITS_PER_LONG. Share the CFG_MATCH ecall through a small helper so the 32-bit argument split is not duplicated. On qemu-system-riscv32 the probe bitmap has bits above XLEN set, so the first word alone is not enough. [[email protected]: updated to apply; fixed checkpatch.pl issues]
INFO
Published Date :
Sept. 25, 2026, 11:17 a.m.
Last Modified :
Sept. 25, 2026, 11:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to the patched version.
- Apply the specific perf fix for RISC-V.
- Ensure correct bitmap handling for counters.
- Validate counter mask iteration on RV32.
References to Advisories, Solutions, and Tools
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information, practical solutions, and valuable tools related to
CVE-2026-97587.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-97587 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-97587
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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CVE-2026-97587 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-97587 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 25, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: perf: RISC-V: store available counter mask as bitmap The available-counter mask was a single unsigned long, but iteration uses RISCV_MAX_COUNTERS, which is 64. On RV32 that reads past the object. Filling with an unsigned-long bit at index 32 and above is also wrong. Use DECLARE_BITMAP and set_bit/bitmap helpers. Walk each bitmap word into CFG_MATCH when checking events, when allocating an index, and when stopping all counters. Set the counter base to i times BITS_PER_LONG. Share the CFG_MATCH ecall through a small helper so the 32-bit argument split is not duplicated. On qemu-system-riscv32 the probe bitmap has bits above XLEN set, so the first word alone is not enough. [[email protected]: updated to apply; fixed checkpatch.pl issues] Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/97xxx/CVE-2026-97587.json">CVE-2026-97587</a> Added Reference https://git.kernel.org/stable/c/143668c424772979a45118dc9cc9c2c13a35f41d Added Reference https://git.kernel.org/stable/c/6809da6e9c08ccc9a09cb0a48c61471679274aaa Added Reference https://git.kernel.org/stable/c/9bec7beaed074bcae4181fde9ff9dfbe4e7b0957 Added Reference https://git.kernel.org/stable/c/e5481db31f4654e9a1254d5d467d9b1ff2f8b1cb