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authorMike Rapoport <rppt@linux.vnet.ibm.com>2017-03-09 16:17:09 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-03-09 17:01:10 -0800
commit7eb76d457fd758d396bc2e65cb0ace5aae614149 (patch)
tree65cef25c2ccabe3574891256e13292939270bdce
parentbfc7228b9a9647e1c353e50b40297a2929801759 (diff)
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 <rppt@linux.vnet.ibm.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Andrea 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/userfaultfd.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index dd48052e086f..2407249998c3 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;
}

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