From: John Hubbard jhubbard@nvidia.com
commit ffca476a0a8d26de767cc41d62b8ca7f540ecfdd upstream.
In the case of get_user_pages_fast() returning fewer pages than requested, rio_dma_transfer() does not quite do the right thing. It attempts to release all the pages that were requested, rather than just the pages that were pinned.
Fix the error handling so that only the pages that were successfully pinned are released.
Fixes: e8de370188d0 ("rapidio: add mport char device driver") Signed-off-by: John Hubbard jhubbard@nvidia.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Reviewed-by: Andrew Morton akpm@linux-foundation.org Cc: Matt Porter mporter@kernel.crashing.org Cc: Alexandre Bounine alex.bou9@gmail.com Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Dan Carpenter dan.carpenter@oracle.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20200517235620.205225-2-jhubbard@nvidia.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/rapidio/devices/rio_mport_cdev.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/rapidio/devices/rio_mport_cdev.c +++ b/drivers/rapidio/devices/rio_mport_cdev.c @@ -877,6 +877,11 @@ rio_dma_transfer(struct file *filp, u32 rmcd_error("pinned %ld out of %ld pages", pinned, nr_pages); ret = -EFAULT; + /* + * Set nr_pages up to mean "how many pages to unpin, in + * the error handler: + */ + nr_pages = pinned; goto err_pg; }