Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Alexei Starovoitov says:

====================
pull-request: bpf 2020-05-29

The following pull-request contains BPF updates for your *net* tree.

We've added 6 non-merge commits during the last 7 day(s) which contain
a total of 4 files changed, 55 insertions(+), 34 deletions(-).

The main changes are:

1) minor verifier fix for fmod_ret progs, from Alexei.

2) af_xdp overflow check, from Bjorn.

3) minor verifier fix for 32bit assignment, from John.

4) powerpc has non-overlapping addr space, from Petr.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 18 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 8d7ee40e2748..efe14cf24bc6 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1168,14 +1168,14 @@ static void __reg_assign_32_into_64(struct bpf_reg_state *reg)
 	 * but must be positive otherwise set to worse case bounds
 	 * and refine later from tnum.
 	 */
-	if (reg->s32_min_value > 0)
-		reg->smin_value = reg->s32_min_value;
-	else
-		reg->smin_value = 0;
-	if (reg->s32_max_value > 0)
+	if (reg->s32_min_value >= 0 && reg->s32_max_value >= 0)
 		reg->smax_value = reg->s32_max_value;
 	else
 		reg->smax_value = U32_MAX;
+	if (reg->s32_min_value >= 0)
+		reg->smin_value = reg->s32_min_value;
+	else
+		reg->smin_value = 0;
 }
 
 static void __reg_combine_32_into_64(struct bpf_reg_state *reg)
@@ -10428,22 +10428,13 @@ static int check_struct_ops_btf_id(struct bpf_verifier_env *env)
 }
 #define SECURITY_PREFIX "security_"
 
-static int check_attach_modify_return(struct bpf_verifier_env *env)
+static int check_attach_modify_return(struct bpf_prog *prog, unsigned long addr)
 {
-	struct bpf_prog *prog = env->prog;
-	unsigned long addr = (unsigned long) prog->aux->trampoline->func.addr;
-
-	/* This is expected to be cleaned up in the future with the KRSI effort
-	 * introducing the LSM_HOOK macro for cleaning up lsm_hooks.h.
-	 */
 	if (within_error_injection_list(addr) ||
 	    !strncmp(SECURITY_PREFIX, prog->aux->attach_func_name,
 		     sizeof(SECURITY_PREFIX) - 1))
 		return 0;
 
-	verbose(env, "fmod_ret attach_btf_id %u (%s) is not modifiable\n",
-		prog->aux->attach_btf_id, prog->aux->attach_func_name);
-
 	return -EINVAL;
 }
 
@@ -10654,11 +10645,18 @@ static int check_attach_btf_id(struct bpf_verifier_env *env)
 				goto out;
 			}
 		}
+
+		if (prog->expected_attach_type == BPF_MODIFY_RETURN) {
+			ret = check_attach_modify_return(prog, addr);
+			if (ret)
+				verbose(env, "%s() is not modifiable\n",
+					prog->aux->attach_func_name);
+		}
+
+		if (ret)
+			goto out;
 		tr->func.addr = (void *)addr;
 		prog->aux->trampoline = tr;
-
-		if (prog->expected_attach_type == BPF_MODIFY_RETURN)
-			ret = check_attach_modify_return(env);
 out:
 		mutex_unlock(&tr->mutex);
 		if (ret)