eCryptfs: Return error when lower file pointer is NULL
Tyler Hicks [Fri, 5 Aug 2011 03:58:51 +0000 (22:58 -0500)]
When an eCryptfs inode's lower file has been closed, and the pointer has
been set to NULL, return an error when trying to do a lower read or
write rather than calling BUG().

https://bugzilla.kernel.org/show_bug.cgi?id=37292

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: <stable@kernel.org>

fs/ecryptfs/read_write.c

index 85d4309..3745f7c 100644 (file)
 int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
                         loff_t offset, size_t size)
 {
-       struct ecryptfs_inode_info *inode_info;
+       struct file *lower_file;
        mm_segment_t fs_save;
        ssize_t rc;
 
-       inode_info = ecryptfs_inode_to_private(ecryptfs_inode);
-       BUG_ON(!inode_info->lower_file);
+       lower_file = ecryptfs_inode_to_private(ecryptfs_inode)->lower_file;
+       if (!lower_file)
+               return -EIO;
        fs_save = get_fs();
        set_fs(get_ds());
-       rc = vfs_write(inode_info->lower_file, data, size, &offset);
+       rc = vfs_write(lower_file, data, size, &offset);
        set_fs(fs_save);
        mark_inode_dirty_sync(ecryptfs_inode);
        return rc;
@@ -225,15 +226,16 @@ out:
 int ecryptfs_read_lower(char *data, loff_t offset, size_t size,
                        struct inode *ecryptfs_inode)
 {
-       struct ecryptfs_inode_info *inode_info =
-               ecryptfs_inode_to_private(ecryptfs_inode);
+       struct file *lower_file;
        mm_segment_t fs_save;
        ssize_t rc;
 
-       BUG_ON(!inode_info->lower_file);
+       lower_file = ecryptfs_inode_to_private(ecryptfs_inode)->lower_file;
+       if (!lower_file)
+               return -EIO;
        fs_save = get_fs();
        set_fs(get_ds());
-       rc = vfs_read(inode_info->lower_file, data, size, &offset);
+       rc = vfs_read(lower_file, data, size, &offset);
        set_fs(fs_save);
        return rc;
 }