CVE-2026-97587

Summary

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.

[pjw@kernel.org: updated to apply; fixed checkpatch.pl issues]

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxe9991434596f5373dfd75857b445eb92a9253c56 < 143668c424772979a45118dc9cc9c2c13a35f41daffected
LinuxLinuxe9991434596f5373dfd75857b445eb92a9253c56 < 9bec7beaed074bcae4181fde9ff9dfbe4e7b0957affected
LinuxLinuxe9991434596f5373dfd75857b445eb92a9253c56 < e5481db31f4654e9a1254d5d467d9b1ff2f8b1cbaffected
LinuxLinuxe9991434596f5373dfd75857b445eb92a9253c56 < 6809da6e9c08ccc9a09cb0a48c61471679274aaaaffected
LinuxLinux5.18affected
LinuxLinux0 < 5.18unaffected
LinuxLinux6.12.111 <= 6.12.*unaffected
LinuxLinux6.18.53 <= 6.18.*unaffected
LinuxLinux7.2.7 <= 7.2.*unaffected
LinuxLinux7.3-rc3 <= *unaffected

Weaknesses

References