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@xxxxxxxxxx>
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@xxxxxxxxxxxx>
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Tested-by: Mathias Thore <Mathias.Thore@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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:
--
2.19.1
