CVE-2026-92517: bpf, riscv: Fix extable handling for arena load_acquire

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-17 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: bpf, riscv: Fix extable handling for arena load_acquire emit_atomic_ld_st() returns 1 to have build_body() skip the zext after a sub-word load_acquire. The caller does "ret = ret ?: add_exception_handler(...)", which skips add_exception_handler() on any non-zero ret, so the extable entry is missing and a faulting PROBE_ATOMIC load_acquire oopses. REG_DONT_CLEAR_MARKER leaves rd stale on fault, and the verifier still thinks the load overwrote it, so a program can leak it through a map. Check ret >= 0 before calling add_exception_handler(), and pass rd for LOAD_ACQ so the fault zeroes rd like a PROBE_MEM load. Return ret unchanged for the zext skip.

Affected products

Linux kernel: 6.18 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

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