Commit 511a8cdb authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit 

Pull audit fixes from Paul Moore:
 "Two small patches to fix some bugs with the audit-by-executable
  functionality we introduced back in v4.3 (both patches are marked
  for the stable folks)"

* 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit:
  audit: fix exe_file access in audit_exe_compare
  mm: introduce get_task_exe_file
parents 7d1ce606 5efc2443

fs/proc/base.c

+1 −6
Original line number Diff line number Diff line
@@ -1556,18 +1556,13 @@ static const struct file_operations proc_pid_set_comm_operations = { 
static int proc_exe_link(struct dentry *dentry, struct path *exe_path)

{

	struct task_struct *task;

	struct mm_struct *mm;

	struct file *exe_file;



	task = get_proc_task(d_inode(dentry));

	if (!task)

		return -ENOENT;

	mm = get_task_mm(task);

	exe_file = get_task_exe_file(task);

	put_task_struct(task);

	if (!mm)

		return -ENOENT;

	exe_file = get_mm_exe_file(mm);

	mmput(mm);

	if (exe_file) {

		*exe_path = exe_file->f_path;

		path_get(&exe_file->f_path);

include/linux/mm.h

+1 −0
Original line number Diff line number Diff line
@@ -2014,6 +2014,7 @@ extern void mm_drop_all_locks(struct mm_struct *mm); 


extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);

extern struct file *get_mm_exe_file(struct mm_struct *mm);

extern struct file *get_task_exe_file(struct task_struct *task);



extern bool may_expand_vm(struct mm_struct *, vm_flags_t, unsigned long npages);

extern void vm_stat_account(struct mm_struct *, vm_flags_t, long npages);

kernel/audit_watch.c

+5 −3
Original line number Diff line number Diff line
@@ -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);

}

kernel/fork.c

+23 −0
Original line number Diff line number Diff line
@@ -798,6 +798,29 @@ struct file *get_mm_exe_file(struct mm_struct *mm) 
}

EXPORT_SYMBOL(get_mm_exe_file);



/**

 * get_task_exe_file - acquire a reference to the task's executable file

 *

 * Returns %NULL if task's mm (if any) has no associated executable file or

 * this is a kernel thread with borrowed mm (see the comment above get_task_mm).

 * User must release file via fput().

 */

struct file *get_task_exe_file(struct task_struct *task)

{

	struct file *exe_file = NULL;

	struct mm_struct *mm;



	task_lock(task);

	mm = task->mm;

	if (mm) {

		if (!(task->flags & PF_KTHREAD))

			exe_file = get_mm_exe_file(mm);

	}

	task_unlock(task);

	return exe_file;

}

EXPORT_SYMBOL(get_task_exe_file);



/**

 * get_task_mm - acquire a reference to the task's mm

 *

CRA Git | Maintained and supported by SUSTech CRA and CCSE