This is a note to let you know that I've just added the patch titled

uio: Fix an Oops on load

to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 432798195bbce1f8cd33d1c0284d0538835e25fb Mon Sep 17 00:00:00 2001

From: Dan Carpenter dan.carpenter@oracle.com Date: Fri, 26 Oct 2018 10:19:51 +0300 Subject: uio: Fix an Oops on load

I was trying to solve a double free but I introduced a more serious NULL dereference bug. The problem is that if there is an IRQ which triggers immediately, then we need "info->uio_dev" but it's not set yet.

This patch puts the original initialization back to how it was and just sets info->uio_dev to NULL on the error path so it should solve both the Oops and the double free.

Fixes: f019f07ecf6a ("uio: potential double frees if __uio_register_device() fails") Reported-by: Mathias Thore Mathias.Thore@infinera.com Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Cc: stable stable@vger.kernel.org Tested-by: Mathias Thore Mathias.Thore@infinera.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/uio/uio.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index 85644669fbe7..0a357db4b31b 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -961,6 +961,8 @@ int __uio_register_device(struct module *owner, if (ret) goto err_uio_dev_add_attributes;

+ info->uio_dev = idev; + if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { /* * Note that we deliberately don't use devm_request_irq @@ -972,11 +974,12 @@ int __uio_register_device(struct module *owner, */ ret = request_irq(info->irq, uio_interrupt, info->irq_flags, info->name, idev); - if (ret) + if (ret) { + info->uio_dev = NULL; goto err_request_irq; + } }

- info->uio_dev = idev; return 0;

err_request_irq: