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Commit 7eb76d45 authored by Mike Rapoport's avatar Mike Rapoport Committed by Linus Torvalds
Browse files

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: default avatarMike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Reported-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent bfc7228b

fs/userfaultfd.c

+9 −0
Original line number Diff line number Diff line
@@ -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;

		}