[PATCH] audit: fix audit_exe_compare using get_mm_exe_file
Fix original naive attempt to get/lock access to task->mm->exe_file by
using get_mm_exe_file and checking for NULL.
See: https://lkml.org/lkml/2016/7/30/97
Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com>
---
kernel/audit_watch.c | 13 ++++++++++---
1 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index d6709eb..0b29279 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -19,6 +19,7 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include <linux/file.h>
#include <linux/kernel.h>
#include <linux/audit.h>
#include <linux/kthread.h>
@@ -540,14 +541,20 @@ int audit_dupe_exe(struct audit_krule *new, struct audit_krule
*old)
int audit_exe_compare(struct task_struct *tsk, struct audit_fsnotify_mark *mark)
{
+ struct mm_struct *mm;
struct file *exe_file;
unsigned long ino;
dev_t dev;
- rcu_read_lock();
- exe_file = rcu_dereference(tsk->mm->exe_file);
+ mm = get_task_mm(tsk);
+ if (!mm)
+ return 0;
+ exe_file = get_mm_exe_file(mm);
+ mmput(mm);
+ if (!exe_file)
+ return 0;
ino = exe_file->f_inode->i_ino;
dev = exe_file->f_inode->i_sb->s_dev;
- rcu_read_unlock();
+ fput(exe_file);
return audit_mark_compare(mark, ino, dev);
}
--
1.7.1