1 files changed, 18 insertions, 9 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 1c4ebb326785..01fbef9576e0 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1202,14 +1202,17 @@ static bool is_spilled_scalar_reg64(const struct bpf_stack_state *stack)
 /* Mark stack slot as STACK_MISC, unless it is already STACK_INVALID, in which
  * case they are equivalent, or it's STACK_ZERO, in which case we preserve
  * more precise STACK_ZERO.
- * Note, in uprivileged mode leaving STACK_INVALID is wrong, so we take
- * env->allow_ptr_leaks into account and force STACK_MISC, if necessary.
+ * Regardless of allow_ptr_leaks setting (i.e., privileged or unprivileged
+ * mode), we won't promote STACK_INVALID to STACK_MISC. In privileged case it is
+ * unnecessary as both are considered equivalent when loading data and pruning,
+ * in case of unprivileged mode it will be incorrect to allow reads of invalid
+ * slots.
  */
 static void mark_stack_slot_misc(struct bpf_verifier_env *env, u8 *stype)
 {
 	if (*stype == STACK_ZERO)
 		return;
-	if (env->allow_ptr_leaks && *stype == STACK_INVALID)
+	if (*stype == STACK_INVALID)
 		return;
 	*stype = STACK_MISC;
 }
@@ -4700,6 +4703,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 	 */
 	if (!env->allow_ptr_leaks &&
 	    is_spilled_reg(&state->stack[spi]) &&
+	    !is_spilled_scalar_reg(&state->stack[spi]) &&
 	    size != BPF_REG_SIZE) {
 		verbose(env, "attempt to corrupt spilled pointer on stack\n");
 		return -EACCES;
@@ -8071,7 +8075,7 @@ static int process_dynptr_func(struct bpf_verifier_env *env, int regno, int insn
 	if (reg->type != PTR_TO_STACK && reg->type != CONST_PTR_TO_DYNPTR) {
 		verbose(env,
 			"arg#%d expected pointer to stack or const struct bpf_dynptr\n",
-			regno);
+			regno - 1);
 		return -EINVAL;
 	}
 
@@ -8125,7 +8129,7 @@ static int process_dynptr_func(struct bpf_verifier_env *env, int regno, int insn
 		if (!is_dynptr_reg_valid_init(env, reg)) {
 			verbose(env,
 				"Expected an initialized dynptr as arg #%d\n",
-				regno);
+				regno - 1);
 			return -EINVAL;
 		}
 
@@ -8133,7 +8137,7 @@ static int process_dynptr_func(struct bpf_verifier_env *env, int regno, int insn
 		if (!is_dynptr_type_expected(env, reg, arg_type & ~MEM_RDONLY)) {
 			verbose(env,
 				"Expected a dynptr of type %s as arg #%d\n",
-				dynptr_type_str(arg_to_dynptr_type(arg_type)), regno);
+				dynptr_type_str(arg_to_dynptr_type(arg_type)), regno - 1);
 			return -EINVAL;
 		}
 
@@ -8189,6 +8193,11 @@ static int process_iter_arg(struct bpf_verifier_env *env, int regno, int insn_id
 	const struct btf_type *t;
 	int spi, err, i, nr_slots, btf_id;
 
+	if (reg->type != PTR_TO_STACK) {
+		verbose(env, "arg#%d expected pointer to an iterator on stack\n", regno - 1);
+		return -EINVAL;
+	}
+
 	/* For iter_{new,next,destroy} functions, btf_check_iter_kfuncs()
 	 * ensures struct convention, so we wouldn't need to do any BTF
 	 * validation here. But given iter state can be passed as a parameter
@@ -8197,7 +8206,7 @@ static int process_iter_arg(struct bpf_verifier_env *env, int regno, int insn_id
 	 */
 	btf_id = btf_check_iter_arg(meta->btf, meta->func_proto, regno - 1);
 	if (btf_id < 0) {
-		verbose(env, "expected valid iter pointer as arg #%d\n", regno);
+		verbose(env, "expected valid iter pointer as arg #%d\n", regno - 1);
 		return -EINVAL;
 	}
 	t = btf_type_by_id(meta->btf, btf_id);
@@ -8207,7 +8216,7 @@ static int process_iter_arg(struct bpf_verifier_env *env, int regno, int insn_id
 		/* bpf_iter_<type>_new() expects pointer to uninit iter state */
 		if (!is_iter_reg_valid_uninit(env, reg, nr_slots)) {
 			verbose(env, "expected uninitialized iter_%s as arg #%d\n",
-				iter_type_str(meta->btf, btf_id), regno);
+				iter_type_str(meta->btf, btf_id), regno - 1);
 			return -EINVAL;
 		}
 
@@ -8231,7 +8240,7 @@ static int process_iter_arg(struct bpf_verifier_env *env, int regno, int insn_id
 			break;
 		case -EINVAL:
 			verbose(env, "expected an initialized iter_%s as arg #%d\n",
-				iter_type_str(meta->btf, btf_id), regno);
+				iter_type_str(meta->btf, btf_id), regno - 1);
 			return err;
 		case -EPROTO:
 			verbose(env, "expected an RCU CS when using %s\n", meta->func_name);