diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index a5255a0dcbb6..243d06ce6842 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -11822,10 +11822,17 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env, * register B - not null * for JNE A, B, ... - A is not null in the false branch; * for JEQ A, B, ... - A is not null in the true branch. + * + * Since PTR_TO_BTF_ID points to a kernel struct that does + * not need to be null checked by the BPF program, i.e., + * could be null even without PTR_MAYBE_NULL marking, so + * only propagate nullness when neither reg is that type. */ if (!is_jmp32 && BPF_SRC(insn->code) == BPF_X && __is_pointer_value(false, src_reg) && __is_pointer_value(false, dst_reg) && - type_may_be_null(src_reg->type) != type_may_be_null(dst_reg->type)) { + type_may_be_null(src_reg->type) != type_may_be_null(dst_reg->type) && + base_type(src_reg->type) != PTR_TO_BTF_ID && + base_type(dst_reg->type) != PTR_TO_BTF_ID) { eq_branch_regs = NULL; switch (opcode) { case BPF_JEQ: |