CVE-2026-92517 bpf, riscv: Fix extable handling for arena load_acquire
A local attacker can leak stale register data via BPF arena load_acquire faults or cause a kernel oops due to missing exception handling in the RISC-V Linux kernel.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-92517?
CVE-2026-92517 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-92517?
How do I fix CVE-2026-92517?
Apply the vendor's patch.
Is CVE-2026-92517 being exploited?
There is no known exploitation of CVE-2026-92517 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-92517, DEBIAN-CVE-2026-92517, GHSA-92r6-5jjc-jv43, UBUNTU-CVE-2026-92517.