[PATCH] ecryptfs: Fix explicit null dereference

[Geyslan G. Bem]

If the condition 'ecryptfs_file_to_private(file)' takes false branch
lower_file is dereferenced when NULL.

Caught by Coverity: CIDs 1128834 and 1128833.

Signed-off-by: Geyslan G. Bem <geyslan@xxxxxxxxx>
---
 fs/ecryptfs/file.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 2229a74..1c0403a 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -316,10 +316,12 @@ ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	struct file *lower_file = NULL;
 	long rc = -ENOTTY;
 
-	if (ecryptfs_file_to_private(file))
-		lower_file = ecryptfs_file_to_lower(file);
+	if (!ecryptfs_file_to_private(file))
+		goto out;
+	lower_file = ecryptfs_file_to_lower(file);
 	if (lower_file->f_op->unlocked_ioctl)
 		rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
+out:
 	return rc;
 }
 
@@ -330,10 +332,12 @@ ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	struct file *lower_file = NULL;
 	long rc = -ENOIOCTLCMD;
 
-	if (ecryptfs_file_to_private(file))
-		lower_file = ecryptfs_file_to_lower(file);
+	if (!ecryptfs_file_to_private(file))
+		goto out;
+	lower_file = ecryptfs_file_to_lower(file);
 	if (lower_file->f_op && lower_file->f_op->compat_ioctl)
 		rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
+out:
 	return rc;
 }
 #endif
-- 
1.8.4.2

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