[PATCH 2/3] ima_fs: Reorder input parameter validation in ima_write_policy()

[SF Markus Elfring]

From: Markus Elfring <elfr...@users.sourceforge.net>
Date: Tue, 24 Jan 2017 22:38:00 +0100

Move validation for the input parameter "ppos" to the beginning in this
function so that a following check for the input parameter "datalen"
can be occasionally avoided earlier.

Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
 security/integrity/ima/ima_fs.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index c1c8d34d111d..98304411915d 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -315,15 +315,14 @@ static ssize_t ima_write_policy(struct file *file, const 
char __user *buf,
        char *data;
        ssize_t result;
 
-       if (datalen >= PAGE_SIZE)
-               datalen = PAGE_SIZE - 1;
-
        /* No partial writes. */
        result = -EINVAL;
        if (*ppos != 0)
                goto reset_validity;
 
        result = -ENOMEM;
+       if (datalen >= PAGE_SIZE)
+               datalen = PAGE_SIZE - 1;
        data = kmalloc(datalen + 1, GFP_KERNEL);
        if (!data)
                goto reset_validity;
-- 
2.11.0