From: John Hubbard <jhubbard@xxxxxxxxxx> Subject: rapidio: fix an error in get_user_pages_fast() error handling 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. Link: http://lkml.kernel.org/r/20200517235620.205225-2-jhubbard@xxxxxxxxxx Fixes: e8de370188d0 ("rapidio: add mport char device driver") Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx> Cc: Alexandre Bounine <alex.bou9@xxxxxxxxx> Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/rapidio/devices/rio_mport_cdev.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/rapidio/devices/rio_mport_cdev.c~rapidio-fix-an-error-in-get_user_pages_fast-error-handling +++ a/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; } _
