Don't panic if accounts are shorter than 8 bytes

client/src/chain_data_fetcher.rs

@@ -38,6 +38,13 @@ impl AccountFetcher {
         let acc = self.fetch_raw(address)?;
 
         let data = acc.data();
+        if data.len() < 8 {
+            anyhow::bail!(
+                "account at {} has only {} bytes of data",
+                address,
+                data.len()
+            );
+        }
         let disc_bytes = &data[0..8];
         if disc_bytes != MangoAccount::discriminator() {
             anyhow::bail!("not a mango account at {}", address);

liquidator/src/util.rs

@@ -12,7 +12,7 @@ pub fn is_mango_account<'a>(
     group_id: &Pubkey,
 ) -> Option<MangoAccountRefWithHeader<'a>> {
     let data = account.data();
-    if account.owner() != program_id || data.is_empty() {
+    if account.owner() != program_id || data.len() < 8 {
         return None;
     }
 
@@ -37,7 +37,7 @@ pub fn is_mango_bank<'a>(
     group_id: &Pubkey,
 ) -> Option<&'a Bank> {
     let data = account.data();
-    if account.owner() != program_id || data.is_empty() {
+    if account.owner() != program_id || data.len() < 8 {
         return None;
     }
 
@@ -61,7 +61,7 @@ pub fn is_mint_info<'a>(
     group_id: &Pubkey,
 ) -> Option<&'a MintInfo> {
     let data = account.data();
-    if account.owner() != program_id || data.is_empty() {
+    if account.owner() != program_id || data.len() < 8 {
         return None;
     }
 
@@ -85,7 +85,7 @@ pub fn is_perp_market<'a>(
     group_id: &Pubkey,
 ) -> Option<&'a PerpMarket> {
     let data = account.data();
-    if account.owner() != program_id || data.is_empty() {
+    if account.owner() != program_id || data.len() < 8 {
         return None;
     }
 

programs/mango-v4/src/accounts_zerocopy.rs

@@ -157,6 +157,9 @@ impl<A: AccountReader> LoadZeroCopy for A {
         }
 
         let data = self.data();
+        if data.len() < 8 {
+            return Err(ErrorCode::AccountDiscriminatorNotFound.into());
+        }
         let disc_bytes = array_ref![data, 0, 8];
         if disc_bytes != &T::discriminator() {
             return Err(ErrorCode::AccountDiscriminatorMismatch.into());
@@ -178,6 +181,9 @@ impl<'info, 'a> LoadMutZeroCopy for AccountInfoRefMut<'info, 'a> {
             return Err(ErrorCode::AccountOwnedByWrongProgram.into());
         }
 
+        if self.data.len() < 8 {
+            return Err(ErrorCode::AccountDiscriminatorNotFound.into());
+        }
         let disc_bytes = array_ref![self.data, 0, 8];
         if disc_bytes != &T::discriminator() {
             return Err(ErrorCode::AccountDiscriminatorMismatch.into());
@@ -202,6 +208,9 @@ impl<'info> LoadZeroCopyRef for AccountInfo<'info> {
         }
 
         let data = self.try_borrow_data()?;
+        if data.len() < 8 {
+            return Err(ErrorCode::AccountDiscriminatorNotFound.into());
+        }
 
         let disc_bytes = array_ref![data, 0, 8];
         if disc_bytes != &T::discriminator() {
@@ -228,6 +237,9 @@ impl<'info> LoadMutZeroCopyRef for AccountInfo<'info> {
         }
 
         let data = self.try_borrow_mut_data()?;
+        if data.len() < 8 {
+            return Err(ErrorCode::AccountDiscriminatorNotFound.into());
+        }
 
         let disc_bytes = array_ref![data, 0, 8];
         if disc_bytes != &T::discriminator() {

programs/mango-v4/src/state/health.rs

@@ -189,6 +189,7 @@ fn can_load_as<'a, T: ZeroCopy + Owner>(
     match load_result {
         Err(Error::AnchorError(error))
             if error.error_code_number == ErrorCode::AccountDiscriminatorMismatch as u32
+                || error.error_code_number == ErrorCode::AccountDiscriminatorNotFound as u32
                 || error.error_code_number == ErrorCode::AccountOwnedByWrongProgram as u32 =>
         {
             return None;