fanotify: Dont allow a mask of 0 if setting or removing a mark

In mark_remove_from_mask() we destroy marks that have their event mask cleared.
Thus we should not allow the creation of those marks in the first place.
With this patch we check if the mask given from user is 0 in case of FAN_MARK_ADD.
If so we return an error. Same for FAN_MARK_REMOVE since this does not have any
effect.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
This commit is contained in:
Lino Sanfilippo 2010-11-22 18:46:33 +01:00 committed by Eric Paris
parent fa218ab98c
commit 1734dee4e3

View File

@ -769,8 +769,10 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags,
if (flags & ~FAN_ALL_MARK_FLAGS)
return -EINVAL;
switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) {
case FAN_MARK_ADD:
case FAN_MARK_ADD: /* fallthrough */
case FAN_MARK_REMOVE:
if (!mask)
return -EINVAL;
case FAN_MARK_FLUSH:
break;
default: