[BUG]: fix prevent illegal memory access in Mamba SSM tracking during EAGLE speculative verification (#19415)

Co-authored-by: ConnorLi96 <ConnorLi96@users.noreply.github.com>

python/sglang/srt/speculative/eagle_info.py

@@ -154,6 +154,8 @@ class EagleVerifyInput(SpecInput, EagleVerifyInputV2Mixin):
                 dtype=torch.int64,
                 device=batch.device,
             )
+            batch.mamba_track_mask = None
+            batch.mamba_track_seqlens = None
 
     def generate_attn_arg_prefill(
         self,

python/sglang/srt/speculative/eagle_info_v2.py

@@ -242,6 +242,8 @@ class EagleVerifyInputV2Mixin:
                     dtype=torch.int64,
                     device=device,
                 )
+                batch.mamba_track_mask = None
+                batch.mamba_track_seqlens = None
 
         # Get a forward batch
         batch.forward_mode = (