From ba324dbbc25fa83c3e569a5f43b0bd69350ae722 Mon Sep 17 00:00:00 2001 From: John Hubbard Date: Fri, 22 May 2020 22:22:48 -0700 Subject: [PATCH] rapidio: fix an error in get_user_pages_fast() error handling 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 Signed-off-by: Andrew Morton Reviewed-by: Andrew Morton Cc: Matt Porter Cc: Alexandre Bounine Cc: Sumit Semwal Cc: Dan Carpenter Cc: Link: http://lkml.kernel.org/r/20200517235620.205225-2-jhubbard@nvidia.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/rapidio/devices/rio_mport_cdev.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c index 28c45db45aba..ebe8e8dc4677 100644 --- a/drivers/rapidio/devices/rio_mport_cdev.c +++ b/drivers/rapidio/devices/rio_mport_cdev.c @@ -905,6 +905,11 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode, 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; }