From fa63f083b3492b5ed5332b8d7c90b03b5ef24a1d Mon Sep 17 00:00:00 2001 From: Souptick Joarder Date: Thu, 15 Oct 2020 20:13:15 -0700 Subject: rapidio: fix error handling path rio_dma_transfer() attempts to clamp the return value of pin_user_pages_fast() to be >= 0. However, the attempt fails because nr_pages is overridden a few lines later, and restored to the undesirable -ERRNO value. The return value is ultimately stored in nr_pages, which in turn is passed to unpin_user_pages(), which expects nr_pages >= 0, else, disaster. Fix this by fixing the nesting of the assignment to nr_pages: nr_pages should be clamped to zero if pin_user_pages_fast() returns -ERRNO, or set to the return value of pin_user_pages_fast(), otherwise. [jhubbard@nvidia.com: new changelog] Fixes: e8de370188d09 ("rapidio: add mport char device driver") Signed-off-by: Souptick Joarder Signed-off-by: Andrew Morton Reviewed-by: Ira Weiny Reviewed-by: John Hubbard Cc: Matthew Wilcox Cc: Matt Porter Cc: Alexandre Bounine Cc: Gustavo A. R. Silva Cc: Madhuparna Bhowmik Cc: Dan Carpenter Link: https://lkml.kernel.org/r/1600227737-20785-1-git-send-email-jrdr.linux@gmail.com Signed-off-by: Linus Torvalds --- drivers/rapidio/devices/rio_mport_cdev.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'drivers/rapidio') diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c index a30342942e26..163b6c72501d 100644 --- a/drivers/rapidio/devices/rio_mport_cdev.c +++ b/drivers/rapidio/devices/rio_mport_cdev.c @@ -871,15 +871,16 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode, rmcd_error("pin_user_pages_fast err=%ld", pinned); nr_pages = 0; - } else + } else { rmcd_error("pinned %ld out of %ld pages", pinned, nr_pages); + /* + * Set nr_pages up to mean "how many pages to unpin, in + * the error handler: + */ + nr_pages = pinned; + } ret = -EFAULT; - /* - * Set nr_pages up to mean "how many pages to unpin, in - * the error handler: - */ - nr_pages = pinned; goto err_pg; } -- cgit