CVEvulnerability
CVE-2026-93135
- Status
- Received
- Published
- 2026-09-17
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: Reject programs with inlined helpers if JIT is not available
When an architecture (such as LoongArch, ARM64, and RISC-V) implements
bpf_jit_inlines_helper_call(), the verifier skips rewriting the helper
call offset (insn->imm) in bpf_do_misc_fixups(). This is because the
helper is expected to be inlined by the JIT compiler later. Therefore,
insn->imm remains as the raw helper enum ID.
However, if JIT is disabled at runtime (net.core.bpf_jit_enable=0) or
if JIT compilation fails dynamically (e.g., due to OOM), the program
falls back to the BPF interpreter.
When the interpreter executes (__bpf_call_base + insn->imm) with the
unpatched raw ID, it jumps into an invalid address space, triggering
an instruction alignment fault or a kernel panic.
Although these helpers have valid C implementations in the kernel, the
omission of offset rewriting makes runtime interpreter fallback fatal.
Fix this by setting 'prog->jit_required = 1' when helper call rewriting
is skipped for JIT inlining. This ensures that such programs are safely
rejected if JIT is not available, preventing the runtime kernel panic.