[PATCH 3.12 221/235] apparmor: fix arg_size computation for when setprocattr is null terminated

[Jiri Slaby]

From: John Johansen <john.johansen@xxxxxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit d4d03f74a73f3b8b2801d4d02011b6b69778cbcc upstream.

Signed-off-by: John Johansen <john.johansen@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 security/apparmor/lsm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 90905af74a8d..c623e4744f55 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -562,7 +562,7 @@ static int apparmor_setprocattr(struct task_struct *task, char *name,
 	if (!*args)
 		goto out;
 
-	arg_size = size - (args - (char *) value);
+	arg_size = size - (args - (largs ? largs : (char *) value));
 	if (strcmp(name, "current") == 0) {
 		if (strcmp(command, "changehat") == 0) {
 			error = aa_setprocattr_changehat(args, arg_size,
-- 
2.11.0