diff --git a/deepspeed/inference/v2/inference_utils.py b/deepspeed/inference/v2/inference_utils.py
index 7b2dd4237353..774f74d06ee4 100644
--- a/deepspeed/inference/v2/inference_utils.py
+++ b/deepspeed/inference/v2/inference_utils.py
@@ -8,6 +8,7 @@
 import torch
 
 from enum import Enum, IntEnum
+from deepspeed.utils.validation import ensure_nonzero_divisor
 
 
 class NormTypeEnum(Enum):
@@ -102,4 +103,5 @@ def ceil_div(a: int, b: int) -> int:
     """
     Return ceil(a / b).
     """
+    ensure_nonzero_divisor(b, name="b")
     return -(-a // b)
diff --git a/deepspeed/utils/groups.py b/deepspeed/utils/groups.py
index a6f0a7228977..55f98d7faed0 100644
--- a/deepspeed/utils/groups.py
+++ b/deepspeed/utils/groups.py
@@ -29,6 +29,7 @@
 from deepspeed.utils import log_dist
 from deepspeed.utils.bwc import bwc_tensor_model_parallel_world_size, bwc_pipeline_parallel_world_size
 from deepspeed.utils.exceptions import DeprecatedException
+from deepspeed.utils.validation import ensure_nonzero_divisor
 from deepspeed.accelerator import get_accelerator
 
 # Expert parallel group that the current rank belongs to.
@@ -63,6 +64,7 @@ def initialize(ep_size=1, mpu=None):
 
 def _ensure_divisibility(numerator, denominator):
     """Ensure that numerator is divisible by the denominator."""
+    ensure_nonzero_divisor(denominator, name="denominator")
     assert numerator % denominator == 0, '{} is not divisible by {}'.format(numerator, denominator)
 
 
diff --git a/deepspeed/utils/timer.py b/deepspeed/utils/timer.py
index 0aa7be55d829..532edee7742e 100755
--- a/deepspeed/utils/timer.py
+++ b/deepspeed/utils/timer.py
@@ -4,6 +4,7 @@
 # DeepSpeed Team
 
 import time
+import numbers
 from numpy import mean
 from deepspeed.utils.logging import print_dist
 from deepspeed.accelerator import get_accelerator
@@ -211,7 +212,16 @@ def __init__(self, config, batch_size, start_step=2, steps_per_output=None, moni
         self.global_step_count = 0
         self.total_elapsed_time = 0
         self.step_elapsed_time = 0
-        self.steps_per_output = steps_per_output
+        if steps_per_output is not None:
+            if not isinstance(steps_per_output, numbers.Integral):
+                raise ValueError(
+                    f"steps_per_output must be a positive integer or None, got {type(steps_per_output).__name__}"
+                )
+            if steps_per_output <= 0:
+                raise ValueError(f"steps_per_output must be greater than 0, got {steps_per_output}")
+            self.steps_per_output = int(steps_per_output)
+        else:
+            self.steps_per_output = None
         self.monitor_memory = monitor_memory
         self.logging = logging_fn
         if self.logging is None:
diff --git a/deepspeed/utils/validation.py b/deepspeed/utils/validation.py
new file mode 100644
index 000000000000..28510169b5ff
--- /dev/null
+++ b/deepspeed/utils/validation.py
@@ -0,0 +1,14 @@
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: Apache-2.0
+
+# DeepSpeed Team
+
+from typing import Any
+
+
+def ensure_nonzero_divisor(divisor: Any, *, name: str = "divisor") -> None:
+    """
+    Validate that a divisor is non-zero before modulo/division math.
+    """
+    if divisor == 0:
+        raise ValueError(f"{name} must be non-zero")
diff --git a/op_builder/hpu/fp_quantizer.py b/op_builder/hpu/fp_quantizer.py
index c74affb55045..855e589bcdd1 100644
--- a/op_builder/hpu/fp_quantizer.py
+++ b/op_builder/hpu/fp_quantizer.py
@@ -56,6 +56,11 @@ def selective_dequantize(cls, val_q, scales, indexes, group_size, q_mantisa_bits
     def dequantize(cls, fp_out, input_q, scale, group_size, q_mantisa_bits, q_exponent_bits):
         orig_shape = fp_out.shape
         orig_dtype = fp_out.dtype
+        scale_tensor = scale if torch.is_tensor(scale) else torch.as_tensor(scale)
+        if not torch.all(torch.isfinite(scale_tensor)):
+            raise ValueError("dequantize scale must contain finite values")
+        if torch.any(scale_tensor == 0):
+            raise ValueError("dequantize scale must be non-zero")
         dequant_out = torch.ops.hpu.cast_from_fp8(input_q, (1.0 / scale), orig_dtype).view(orig_shape)
         fp_out.copy_(dequant_out)
         return fp_out
diff --git a/tests/unit/inference/test_inference_utils.py b/tests/unit/inference/test_inference_utils.py
new file mode 100644
index 000000000000..f985afc56f52
--- /dev/null
+++ b/tests/unit/inference/test_inference_utils.py
@@ -0,0 +1,18 @@
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: Apache-2.0
+
+# DeepSpeed Team
+
+import pytest
+
+from deepspeed.inference.v2.inference_utils import ceil_div
+
+
+def test_ceil_div_basic_behavior():
+    assert ceil_div(10, 4) == 3
+    assert ceil_div(12, 4) == 3
+
+
+def test_ceil_div_rejects_zero_divisor():
+    with pytest.raises(ValueError, match="b must be non-zero"):
+        ceil_div(10, 0)
diff --git a/tests/unit/ops/fp_quantizer/test_fp_quantizer_scale_validation.py b/tests/unit/ops/fp_quantizer/test_fp_quantizer_scale_validation.py
new file mode 100644
index 000000000000..f835269c2574
--- /dev/null
+++ b/tests/unit/ops/fp_quantizer/test_fp_quantizer_scale_validation.py
@@ -0,0 +1,27 @@
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: Apache-2.0
+
+# DeepSpeed Team
+
+import pytest
+import torch
+
+from op_builder.hpu.fp_quantizer import FPQuantizer
+
+
+def test_dequantize_rejects_non_finite_scale():
+    fp_out = torch.zeros(4, dtype=torch.float16)
+    input_q = torch.zeros(4, dtype=torch.uint8)
+    scale = torch.tensor([float("inf")], dtype=torch.float32)
+
+    with pytest.raises(ValueError, match="dequantize scale must contain finite values"):
+        FPQuantizer.dequantize(fp_out, input_q, scale, group_size=1, q_mantisa_bits=3, q_exponent_bits=4)
+
+
+def test_dequantize_rejects_zero_scale():
+    fp_out = torch.zeros(4, dtype=torch.float16)
+    input_q = torch.zeros(4, dtype=torch.uint8)
+    scale = torch.tensor([0.0], dtype=torch.float32)
+
+    with pytest.raises(ValueError, match="dequantize scale must be non-zero"):
+        FPQuantizer.dequantize(fp_out, input_q, scale, group_size=1, q_mantisa_bits=3, q_exponent_bits=4)
diff --git a/tests/unit/utils/test_groups.py b/tests/unit/utils/test_groups.py
index 5cd35baf3510..5450b88a02da 100644
--- a/tests/unit/utils/test_groups.py
+++ b/tests/unit/utils/test_groups.py
@@ -3,7 +3,8 @@
 
 # DeepSpeed Team
 
-from deepspeed.utils.groups import _get_expert_parallel_ranks
+import pytest
+from deepspeed.utils.groups import _ensure_divisibility, _get_expert_parallel_ranks
 
 
 def test_get_expert_parallel_ranks():
@@ -36,3 +37,8 @@ def test_get_expert_parallel_ranks():
         [5, 13],
         [7, 15],
     ]
+
+
+def test_ensure_divisibility_rejects_zero_denominator():
+    with pytest.raises(ValueError, match="denominator must be non-zero"):
+        _ensure_divisibility(8, 0)
diff --git a/tests/unit/utils/test_timer.py b/tests/unit/utils/test_timer.py
new file mode 100644
index 000000000000..9563d856d81d
--- /dev/null
+++ b/tests/unit/utils/test_timer.py
@@ -0,0 +1,29 @@
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: Apache-2.0
+
+# DeepSpeed Team
+
+from types import SimpleNamespace
+import pytest
+
+from deepspeed.utils.timer import ThroughputTimer
+
+
+def _timer_config():
+    return SimpleNamespace(enabled=True, synchronized=False)
+
+
+def test_steps_per_output_rejects_zero():
+    with pytest.raises(ValueError, match="steps_per_output must be greater than 0"):
+        ThroughputTimer(config=_timer_config(), batch_size=1, steps_per_output=0)
+
+
+def test_steps_per_output_rejects_non_integral():
+    with pytest.raises(ValueError, match="steps_per_output must be a positive integer or None"):
+        ThroughputTimer(config=_timer_config(), batch_size=1, steps_per_output=1.5)
+
+
+def test_report_boundary_for_valid_steps_per_output():
+    timer = ThroughputTimer(config=_timer_config(), batch_size=1, steps_per_output=3)
+    timer.global_step_count = 6
+    assert timer._is_report_boundary()