Always check context access if the register we're operating on is
PTR_TO_CTX, rather than relying on ARG_PTR_TO_CTX. This allows
simplifying the arg_type checking section of the function.
Signed-off-by: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
Acked-by: Martin KaFai Lau <kafai@xxxxxx>
---
kernel/bpf/verifier.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 0f7a9c65db5c..7d0f9ba18916 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3974,9 +3974,6 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
arg_type == ARG_PTR_TO_CTX_OR_NULL)) {
if (type != expected_type)
goto err_type;
- err = check_ctx_reg(env, reg, regno);
- if (err < 0)
- return err;
}
} else if (arg_type == ARG_PTR_TO_SOCK_COMMON) {
expected_type = PTR_TO_SOCK_COMMON;
@@ -4060,6 +4057,10 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
regno);
return -EACCES;
}
+ } else if (type == PTR_TO_CTX) {
+ err = check_ctx_reg(env, reg, regno);
+ if (err < 0)
+ return err;
}
if (reg->ref_obj_id) {
--
2.25.1
