Fix in-extent reading

diff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c
index d508d75b94c8080e843b37760cb6fa7b841fccd2..ac61452db05d0ca72652c9b26ec41def19e082bc 100644 (file)
--- a/grub-core/fs/btrfs.c
+++ b/grub-core/fs/btrfs.c
@@ -912,6 +912,7 @@ grub_btrfs_read (grub_file_t file, char *buf, grub_size_t len)
   grub_disk_addr_t elemaddr;
   grub_size_t elemsize;
   struct grub_btrfs_key key_in, key_out;
+  grub_off_t extoff;
 
   while (len)
     {
@@ -955,6 +956,7 @@ grub_btrfs_read (grub_file_t file, char *buf, grub_size_t len)
                    grub_le_to_cpu64 (extent->size));
       csize = grub_le_to_cpu64 (extent->size)
        + grub_le_to_cpu64 (key_out.offset) - pos;
+      extoff = pos - grub_le_to_cpu64 (key_out.offset);
       if (csize > len)
        csize = len;
 
@@ -983,7 +985,7 @@ grub_btrfs_read (grub_file_t file, char *buf, grub_size_t len)
       switch (extent->type)
        {
        case GRUB_BTRFS_EXTENT_INLINE:
-         grub_memcpy (buf, extent->inl, csize);
+         grub_memcpy (buf, extent->inl + extoff, csize);
          grub_free (extent);
          break;
        case GRUB_BTRFS_EXTENT_REGULAR:
@@ -993,7 +995,8 @@ grub_btrfs_read (grub_file_t file, char *buf, grub_size_t len)
              break;
            }
          err = grub_btrfs_read_logical (data, file->device->disk,
-                                        grub_le_to_cpu64 (extent->laddr),
+                                        grub_le_to_cpu64 (extent->laddr)
+                                        + extoff,
                                         buf, csize);
          grub_free (extent);
          if (err)