Re: [PATCH] kernel/hung_task: fix address space of proc_dohung_task_timeout_secs

[Conor.Dooley]

On 14/07/2022 08:47, Ben Dooks wrote:

Hey Ben,
Odd CC list here? I assume you're piping get_maintainer into
send-email or something, but idk who is going to see or apply
this patch! Ditto your other one for this file.

Might be worth adding some of what get_maintainer spits out:
Petr Mladek <pmladek@xxxxxxxx> (commit_signer:4/4=100%,authored:1/4=25%,removed_lines:10/15=67%)
Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> (commit_signer:2/4=50%)
Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> (commit_signer:1/4=25%,authored:1/4=25%,removed_lines:1/15=7%)
John Ogness <john.ogness@xxxxxxxxxxxxx> (commit_signer:1/4=25%,authored:1/4=25%,added_lines:10/90=11%,removed_lines:1/15=7%)
Kees Cook <keescook@xxxxxxxxxxxx> (commit_signer:1/4=25%)
Xiaoming Ni <nixiaoming@xxxxxxxxxx> (authored:1/4=25%,added_lines:78/90=87%,removed_lines:3/15=20%)

Thanks,
Conor.


> The proc_dohung_task_timeout_secs() function is incorrectly marked
> as having a __user buffer as argument 3. However this is not the
> case and it is casing multiple sparse warnings. Fix the following
> warnings by removing __user from the argument:
> 
> kernel/hung_task.c:237:52: warning: incorrect type in argument 3 (different address spaces)
> kernel/hung_task.c:237:52:    expected void *
> kernel/hung_task.c:237:52:    got void [noderef] __user *buffer
> kernel/hung_task.c:287:35: warning: incorrect type in initializer (incompatible argument 3 (different address spaces))
> kernel/hung_task.c:287:35:    expected int ( [usertype] *proc_handler )( ... )
> kernel/hung_task.c:287:35:    got int ( * )( ... )
> kernel/hung_task.c:295:35: warning: incorrect type in initializer (incompatible argument 3 (different address spaces))
> kernel/hung_task.c:295:35:    expected int ( [usertype] *proc_handler )( ... )
> kernel/hung_task.c:295:35:    got int ( * )( ... )
> 
> Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxx>
> ---
>   kernel/hung_task.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/hung_task.c b/kernel/hung_task.c
> index cff3ae8c818f..bb2354f73ded 100644
> --- a/kernel/hung_task.c
> +++ b/kernel/hung_task.c
> @@ -229,7 +229,7 @@ static long hung_timeout_jiffies(unsigned long last_checked,
>    * Process updating of timeout sysctl
>    */
>   static int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
> -				  void __user *buffer,
> +				  void *buffer,
>   				  size_t *lenp, loff_t *ppos)
>   {
>   	int ret;