From 7eb76d457fd758d396bc2e65cb0ace5aae614149 Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Thu, 9 Mar 2017 16:17:09 -0800 Subject: [PATCH] userfaultfd: non-cooperative: fix fork fctx->new memleak We have a memleak in the ->new ctx if the uffd of the parent is closed before the fork event is read, nothing frees the new context. Link: http://lkml.kernel.org/r/20170302173738.18994-2-aarcange@redhat.com Signed-off-by: Mike Rapoport Signed-off-by: Andrea Arcangeli Reported-by: Andrea Arcangeli Cc: "Dr. David Alan Gilbert" Cc: Mike Kravetz Cc: Pavel Emelyanov Cc: Hillf Danton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/userfaultfd.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index dd48052e086f6..2407249998c32 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -549,6 +549,15 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx, if (ACCESS_ONCE(ctx->released) || fatal_signal_pending(current)) { __remove_wait_queue(&ctx->event_wqh, &ewq->wq); + if (ewq->msg.event == UFFD_EVENT_FORK) { + struct userfaultfd_ctx *new; + + new = (struct userfaultfd_ctx *) + (unsigned long) + ewq->msg.arg.reserved.reserved1; + + userfaultfd_ctx_put(new); + } break; } -- 2.39.5