[PATCHv2 2/2] audit: fix exe_file access in audit_exe_compare
Prior to the change the function would blindly deference mm, exe_file
and exe_file->f_inode, each of which could have been NULL or freed.
Use get_task_exe_file to safely obtain stable exe_file.
Signed-off-by: Mateusz Guzik <mguzik(a)redhat.com>
Acked-by: Konstantin Khlebnikov <khlebnikov(a)yandex-team.ru>
---
kernel/audit_watch.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index d6709eb..0d302a8 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>
@@ -544,10 +545,11 @@ int audit_exe_compare(struct task_struct *tsk, struct
audit_fsnotify_mark *mark)
unsigned long ino;
dev_t dev;
- rcu_read_lock();
- exe_file = rcu_dereference(tsk->mm->exe_file);
+ exe_file = get_task_exe_file(tsk);
+ 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);
}
--
1.8.3.1