bpf: Add bpf_probe_read_{user, kernel}_str() to do_refine_retval_range

Given bpf_probe_read{,str}() BPF helpers are now only available under
CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE, we need to add the drop-in
replacements of bpf_probe_read_{kernel,user}_str() to do_refine_retval_range()
as well to avoid hitting the same issue as in 849fa50662fbc ("bpf/verifier:
refine retval R0 state for bpf_get_stack helper").

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200515101118.6508-3-daniel@iogearbox.net

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index a44ba66726882539895f7550487cf30aefc3ff82..8d7ee40e2748441bd0036f9fc0528e37255c8d27 100644 (file)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4340,7 +4340,9 @@ static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type,
 
        if (ret_type != RET_INTEGER ||
            (func_id != BPF_FUNC_get_stack &&
-            func_id != BPF_FUNC_probe_read_str))
+            func_id != BPF_FUNC_probe_read_str &&
+            func_id != BPF_FUNC_probe_read_kernel_str &&
+            func_id != BPF_FUNC_probe_read_user_str))
                return;
 
        ret_reg->smax_value = meta->msize_max_value;