From: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
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.
Reported-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
---
fs/userfaultfd.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index d2f15a6..5087a69 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -548,6 +548,15 @@ 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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