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

Commit Message

SF Markus Elfring Jan. 25, 2017, 9:33 a.m. UTC

From: Markus Elfring <[e-mail]>
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 <[e-mail]>
---
 security/integrity/ima/ima_fs.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

Patch

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;