2019-02-14 18:39:47

by Yue Hu

Subject: [PATCH] pstore/ram: Avoid possible failure of dummy device unregister

From 08ac260f36b4c11eb33fa58466462a5e1027bdb3 Mon Sep 17 00:00:00 2001
From: Yue Hu <[email protected]>
Date: Thu, 14 Feb 2019 19:34:16 +0800
Subject: [PATCH] pstore/ram: Avoid possible failure of dummy device unregister

If create dummy platform device failed, dummy variable should not
been set as NULL. Because the following platform_device_unregister()
will judge if the dummy is NULL or not, if dummy is NULL nothing
happen for unregister flow.

Signed-off-by: Yue Hu <[email protected]>
---
fs/pstore/ram.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 4a06675..61bc573 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -994,7 +994,6 @@ static void __init ramoops_register_dummy(void)
if (IS_ERR(dummy)) {
pr_info("could not create platform device: %ld\n",
PTR_ERR(dummy));
- dummy = NULL;
ramoops_unregister_dummy();
}
}
--
1.9.1

2019-02-15 00:53:38

by Kees Cook

Subject: Re: [PATCH] pstore/ram: Avoid possible failure of dummy device unregister

On Thu, Feb 14, 2019 at 3:31 AM Yue Hu <[email protected]> wrote:
>
> From 08ac260f36b4c11eb33fa58466462a5e1027bdb3 Mon Sep 17 00:00:00 2001
> From: Yue Hu <[email protected]>
> Date: Thu, 14 Feb 2019 19:34:16 +0800
> Subject: [PATCH] pstore/ram: Avoid possible failure of dummy device unregister
>
> If create dummy platform device failed, dummy variable should not
> been set as NULL. Because the following platform_device_unregister()
> will judge if the dummy is NULL or not, if dummy is NULL nothing
> happen for unregister flow.
>
> Signed-off-by: Yue Hu <[email protected]>

I've gotten this email a few times today. :)

I already replied that this isn't what we want to do: we have to mark
it NULL since prior to that it was an ERR_PTR, and will break the
unregister.

-Kees

> ---
> fs/pstore/ram.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
> index 4a06675..61bc573 100644
> --- a/fs/pstore/ram.c
> +++ b/fs/pstore/ram.c
> @@ -994,7 +994,6 @@ static void __init ramoops_register_dummy(void)
> if (IS_ERR(dummy)) {
> pr_info("could not create platform device: %ld\n",
> PTR_ERR(dummy));
> - dummy = NULL;
> ramoops_unregister_dummy();
> }
> }
> --
> 1.9.1
>


--
Kees Cook