sanitizes bloom filters to avoid division by zero (#13714) (#13718)

Pull requests received over the wire can cause a validator to panic
because of division by zero in bloom filters:
https://github.com/solana-labs/solana/blob/af08ba93e/runtime/src/bloom.rs#L86-L88

(cherry picked from commit a8c29505f0)

Co-authored-by: behzad nouri <behzadnouri@gmail.com>

runtime/src/bloom.rs

@@ -3,6 +3,7 @@ use bv::BitVec;
 use fnv::FnvHasher;
 use rand::{self, Rng};
 use serde::{Deserialize, Serialize};
+use solana_sdk::sanitize::{Sanitize, SanitizeError};
 use std::fmt;
 use std::sync::atomic::{AtomicU64, Ordering};
 use std::{cmp, hash::Hasher, marker::PhantomData};
@@ -45,7 +46,16 @@ impl<T: BloomHashIndex> fmt::Debug for Bloom<T> {
     }
 }
 
-impl<T: BloomHashIndex> solana_sdk::sanitize::Sanitize for Bloom<T> {}
+impl<T: BloomHashIndex> Sanitize for Bloom<T> {
+    fn sanitize(&self) -> Result<(), SanitizeError> {
+        // Avoid division by zero in self.pos(...).
+        if self.bits.is_empty() {
+            Err(SanitizeError::InvalidValue)
+        } else {
+            Ok(())
+        }
+    }
+}
 
 impl<T: BloomHashIndex> Bloom<T> {
     pub fn new(num_bits: usize, keys: Vec<u64>) -> Self {