The patch titled
Subject: userfaultfd: non-cooperative: fix fork fctx->new memleak
has been added to the -mm tree. Its filename is
userfaultfd-non-cooperative-fix-fork-fctx-new-memleak.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/userfaultfd-non-cooperative-fix-fork-fctx-new-memleak.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/userfaultfd-non-cooperative-fix-fork-fctx-new-memleak.patch
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The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Subject: 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@xxxxxxxxxx
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Reported-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/userfaultfd.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff -puN fs/userfaultfd.c~userfaultfd-non-cooperative-fix-fork-fctx-new-memleak fs/userfaultfd.c
--- a/fs/userfaultfd.c~userfaultfd-non-cooperative-fix-fork-fctx-new-memleak
+++ a/fs/userfaultfd.c
@@ -549,6 +549,15 @@ static void userfaultfd_event_wait_compl
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;
}
_
Patches currently in -mm which might be from rppt@xxxxxxxxxxxxxxxxxx are
userfaultfd-non-cooperative-fix-fork-fctx-new-memleak.patch
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