From 1734dee4e3a296cb72b4819fc2e7ef2440737dff Mon Sep 17 00:00:00 2001 From: Lino Sanfilippo Date: Mon, 22 Nov 2010 18:46:33 +0100 Subject: [PATCH] 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 Signed-off-by: Eric Paris --- fs/notify/fanotify/fanotify_user.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index c0ca1fa1550c..480434c5ee5f 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -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: