diff options
| author | Pavel Begunkov <asml.silence@gmail.com> | 2023-01-22 10:24:20 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-24 07:20:02 +0100 |
| commit | c1a279d79e313bd9b0ed31025edc68394bfc40ab (patch) | |
| tree | 99c7c72a991d5adccc5cfabdba0997abcd306623 | |
| parent | ddaaadf22bea31cf7e94d55c6530ce75947bb1cc (diff) | |
io_uring: fix double poll leak on repolling
commit c0737fa9a5a5cf5a053bcc983f72d58919b997c6 upstream.
We have re-polling for partial IO, so a request can be polled twice. If
it used two poll entries the first time then on the second
io_arm_poll_handler() it will find the old apoll entry and NULL
kmalloc()'ed second entry, i.e. apoll->double_poll, so leaking it.
Fixes: 10c873334feba ("io_uring: allow re-poll if we made progress")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/fee2452494222ecc7f1f88c8fb659baef971414a.1655852245.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | io_uring/io_uring.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 6852878e7762..eb7e3aa85fa3 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -5751,10 +5751,12 @@ static int io_arm_poll_handler(struct io_kiocb *req) mask |= POLLOUT | POLLWRNORM; } - if (req->flags & REQ_F_POLLED) + if (req->flags & REQ_F_POLLED) { apoll = req->apoll; - else + kfree(apoll->double_poll); + } else { apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC); + } if (unlikely(!apoll)) return IO_APOLL_ABORTED; apoll->double_poll = NULL; |