[PATCH 1/2] ipmi: bail out if init_srcu_struct fails

[PATCH 1/2] ipmi: bail out if init_srcu_struct fails

[Thadeu Lima de Souza Cascardo]

In case, init_srcu_struct fails (because of memory allocation failure), we
might proceed with the driver initialization despite srcu_struct not being
entirely initialized.

Fixes: 913a89f009d9 ("ipmi: Don't initialize anything in the core until something uses it")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: Corey Minyard <cminyard@mvista.com>
Cc: stable@vger.kernel.org
---
 drivers/char/ipmi/ipmi_msghandler.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index c837d5416e0e..84975b21fff2 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -5392,7 +5392,9 @@ static int ipmi_init_msghandler(void)
 	if (initialized)
 		goto out;
 
-	init_srcu_struct(&ipmi_interfaces_srcu);
+	rv = init_srcu_struct(&ipmi_interfaces_srcu);
+	if (rv)
+		goto out;
 
 	timer_setup(&ipmi_timer, ipmi_timeout, 0);
 	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
-- 
2.32.0

[PATCH 2/2] ipmi: fix initialization when workqueue allocation fails

[Thadeu Lima de Souza Cascardo]

If the workqueue allocation fails, the driver is marked as not initialized,
and timer and panic_notifier will be left registered.

Instead of removing those when workqueue allocation fails, do the workqueue
initialization before doing it, and cleanup srcu_struct if it fails.

Fixes: 1d49eb91e86e ("ipmi: Move remove_work to dedicated workqueue")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: Corey Minyard <cminyard@mvista.com>
Cc: Ioanna Alifieraki <ioanna-maria.alifieraki@canonical.com>
Cc: stable@vger.kernel.org
---
 drivers/char/ipmi/ipmi_msghandler.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index 84975b21fff2..266c7bc58dda 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -5396,20 +5396,23 @@ static int ipmi_init_msghandler(void)
 	if (rv)
 		goto out;
 
-	timer_setup(&ipmi_timer, ipmi_timeout, 0);
-	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
-
-	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
-
 	remove_work_wq = create_singlethread_workqueue("ipmi-msghandler-remove-wq");
 	if (!remove_work_wq) {
 		pr_err("unable to create ipmi-msghandler-remove-wq workqueue");
 		rv = -ENOMEM;
-		goto out;
+		goto out_wq;
 	}
 
+	timer_setup(&ipmi_timer, ipmi_timeout, 0);
+	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
+
+	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
+
 	initialized = true;
 
+out_wq:
+	if (rv)
+		cleanup_srcu_struct(&ipmi_interfaces_srcu);
 out:
 	mutex_unlock(&ipmi_interfaces_mutex);
 	return rv;
-- 
2.32.0

Re: [PATCH 2/2] ipmi: fix initialization when workqueue allocation fails

[Corey Minyard]

Thanks for this, I need to be more careful about looking at code and not
just looking at patches.  Both in my queue, I'll try to get them in to
5.16.

-corey

On Fri, Dec 17, 2021 at 12:44:10PM -0300, Thadeu Lima de Souza Cascardo wrote:
> If the workqueue allocation fails, the driver is marked as not initialized,
> and timer and panic_notifier will be left registered.
> 
> Instead of removing those when workqueue allocation fails, do the workqueue
> initialization before doing it, and cleanup srcu_struct if it fails.
> 
> Fixes: 1d49eb91e86e ("ipmi: Move remove_work to dedicated workqueue")
> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
> Cc: Corey Minyard <cminyard@mvista.com>
> Cc: Ioanna Alifieraki <ioanna-maria.alifieraki@canonical.com>
> Cc: stable@vger.kernel.org
> ---
>  drivers/char/ipmi/ipmi_msghandler.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> index 84975b21fff2..266c7bc58dda 100644
> --- a/drivers/char/ipmi/ipmi_msghandler.c
> +++ b/drivers/char/ipmi/ipmi_msghandler.c
> @@ -5396,20 +5396,23 @@ static int ipmi_init_msghandler(void)
>  	if (rv)
>  		goto out;
>  
> -	timer_setup(&ipmi_timer, ipmi_timeout, 0);
> -	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
> -
> -	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
> -
>  	remove_work_wq = create_singlethread_workqueue("ipmi-msghandler-remove-wq");
>  	if (!remove_work_wq) {
>  		pr_err("unable to create ipmi-msghandler-remove-wq workqueue");
>  		rv = -ENOMEM;
> -		goto out;
> +		goto out_wq;
>  	}
>  
> +	timer_setup(&ipmi_timer, ipmi_timeout, 0);
> +	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
> +
> +	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
> +
>  	initialized = true;
>  
> +out_wq:
> +	if (rv)
> +		cleanup_srcu_struct(&ipmi_interfaces_srcu);
>  out:
>  	mutex_unlock(&ipmi_interfaces_mutex);
>  	return rv;
> -- 
> 2.32.0
>