Reviewed-by: Marvin Häuser <mhaeuser@posteo.de>

On 27. Jan 2023, at 15:12, Pedro Falcato <pedro.falcato@gmail.com> wrote:

On Fri, Jan 27, 2023 at 9:29 AM Savva Mitrofanov <savvamtr@gmail.com> wrote:

We need to free buffer on return if BlockRemainder != 0. Also changed
return logic from function to use use common exit to prevent code
duplication.

Cc: Marvin Häuser <mhaeuser@posteo.de>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Vitaly Cheptsov <vit9696@protonmail.com>
Fixes: d9ceedca6c8f ("Ext4Pkg: Add Ext4Dxe driver.")
Signed-off-by: Savva Mitrofanov <savvamtr@gmail.com>
---
Features/Ext4Pkg/Ext4Dxe/Directory.c | 30 +++++++++++---------
1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/Features/Ext4Pkg/Ext4Dxe/Directory.c b/Features/Ext4Pkg/Ext4Dxe/Directory.c
index 456916453952..f80b1aacd459 100644
--- a/Features/Ext4Pkg/Ext4Dxe/Directory.c
+++ b/Features/Ext4Pkg/Ext4Dxe/Directory.c
@@ -113,8 +113,7 @@ Ext4RetrieveDirent (
  UINTN           ToCopy;
  UINTN           BlockOffset;

-  Status = EFI_NOT_FOUND;
-  Buf    = AllocatePool (Partition->BlockSize);
+  Buf = AllocatePool (Partition->BlockSize);

  if (Buf == NULL) {
    return EFI_OUT_OF_RESOURCES;
@@ -128,7 +127,8 @@ Ext4RetrieveDirent (
  DivU64x32Remainder (DirInoSize, Partition->BlockSize, &BlockRemainder);
  if (BlockRemainder != 0) {
    // Directory inodes need to have block aligned sizes
-    return EFI_VOLUME_CORRUPTED;
+    Status = EFI_VOLUME_CORRUPTED;
+    goto Out;
  }

  while (Off < DirInoSize) {
@@ -137,8 +137,7 @@ Ext4RetrieveDirent (
    Status = Ext4Read (Partition, Directory, Buf, Off, &Length);

    if (Status != EFI_SUCCESS) {
-      FreePool (Buf);
-      return Status;
+      goto Out;
    }

    for (BlockOffset = 0; BlockOffset < Partition->BlockSize; ) {
@@ -146,19 +145,19 @@ Ext4RetrieveDirent (
      RemainingBlock = Partition->BlockSize - BlockOffset;
      // Check if the minimum directory entry fits inside [BlockOffset, EndOfBlock]
      if (RemainingBlock < EXT4_MIN_DIR_ENTRY_LEN) {
-        FreePool (Buf);
-        return EFI_VOLUME_CORRUPTED;
+        Status = EFI_VOLUME_CORRUPTED;
+        goto Out;
      }

      if (!Ext4ValidDirent (Entry)) {
-        FreePool (Buf);
-        return EFI_VOLUME_CORRUPTED;
+        Status = EFI_VOLUME_CORRUPTED;
+        goto Out;
      }

      if ((Entry->name_len > RemainingBlock) || (Entry->rec_len > RemainingBlock)) {
        // Corrupted filesystem
-        FreePool (Buf);
-        return EFI_VOLUME_CORRUPTED;
+        Status = EFI_VOLUME_CORRUPTED;
+        goto Out;
      }

      // Unused entry
@@ -193,8 +192,8 @@ Ext4RetrieveDirent (
        ToCopy = MIN (Entry->rec_len, sizeof (EXT4_DIR_ENTRY));

        CopyMem (Result, Entry, ToCopy);
-        FreePool (Buf);
-        return EFI_SUCCESS;
+        Status = EFI_SUCCESS;
+        goto Out;
      }

      BlockOffset += Entry->rec_len;
@@ -203,8 +202,11 @@ Ext4RetrieveDirent (
    Off += Partition->BlockSize;
  }

+  Status = EFI_NOT_FOUND;
+
+Out:
  FreePool (Buf);
-  return EFI_NOT_FOUND;
+  return Status;
}

/**
--
2.39.0


Reviewed-by: Pedro Falcato <pedro.falcato@gmail.com>
--
Pedro