[PATCH bpf v2 2/3] bpf: add bpf_probe_read_{user, kernel}_str() to do_refine_retval_range

[Daniel Borkmann]

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 <dan...@iogearbox.net>
Acked-by: John Fastabend <john.fastab...@gmail.com>
Acked-by: Yonghong Song <y...@fb.com>
---
 kernel/bpf/verifier.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index fa1d8245b925..ac922b0d3b00 100644
--- 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;
-- 
2.21.0