* [PATCH] tty: nozomi: Fix a resource leak in an error handling function
@ 2021-05-09 17:22 Christophe JAILLET
2021-05-10 6:35 ` Dan Carpenter
2021-05-10 9:51 ` Jiri Slaby
0 siblings, 2 replies; 3+ messages in thread
From: Christophe JAILLET @ 2021-05-09 17:22 UTC (permalink / raw)
To: gregkh, jirislaby, akpm, stefani
Cc: linux-kernel, kernel-janitors, Christophe JAILLET
A 'request_irq()' call is not balanced by a corresponding 'free_irq()' in
the error handling path, as already done in the remove function.
Add it.
Fixes: 9842c38e9176 ("kfifo: fix warn_unused_result")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
I also wonder if the loop above is correct. The 'i < MAX_PORT' looks really
spurious to me.
'tty_port_destroy' can be called twice for the same entry (once before
branching in the error handling path, and once in here) and
'tty_unregister_device'/'tty_port_destroy' will be called on entries
that have not been 'tty_port_init'ed or 'tty_port_register_device'd.
I don't know if it may be an issue.
---
drivers/tty/nozomi.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c
index 9a2d78ace49b..b270e137ef9b 100644
--- a/drivers/tty/nozomi.c
+++ b/drivers/tty/nozomi.c
@@ -1420,6 +1420,7 @@ static int nozomi_card_init(struct pci_dev *pdev,
tty_unregister_device(ntty_driver, dc->index_start + i);
tty_port_destroy(&dc->port[i].port);
}
+ free_irq(pdev->irq, dc);
err_free_kfifo:
for (i = 0; i < MAX_PORT; i++)
kfifo_free(&dc->port[i].fifo_ul);
--
2.30.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] tty: nozomi: Fix a resource leak in an error handling function
2021-05-09 17:22 [PATCH] tty: nozomi: Fix a resource leak in an error handling function Christophe JAILLET
@ 2021-05-10 6:35 ` Dan Carpenter
2021-05-10 9:51 ` Jiri Slaby
1 sibling, 0 replies; 3+ messages in thread
From: Dan Carpenter @ 2021-05-10 6:35 UTC (permalink / raw)
To: Christophe JAILLET
Cc: gregkh, jirislaby, akpm, stefani, linux-kernel, kernel-janitors
On Sun, May 09, 2021 at 07:22:33PM +0200, Christophe JAILLET wrote:
> A 'request_irq()' call is not balanced by a corresponding 'free_irq()' in
> the error handling path, as already done in the remove function.
>
> Add it.
>
> Fixes: 9842c38e9176 ("kfifo: fix warn_unused_result")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> I also wonder if the loop above is correct. The 'i < MAX_PORT' looks really
> spurious to me.
> 'tty_port_destroy' can be called twice for the same entry (once before
> branching in the error handling path, and once in here) and
> 'tty_unregister_device'/'tty_port_destroy' will be called on entries
> that have not been 'tty_port_init'ed or 'tty_port_register_device'd.
> I don't know if it may be an issue.
Calling tty_port_destroy() twice is fine, but I think calling
tty_unregister_device() for unregistered devices will lead to a NULL
dereference in cdev_del().
regards,
dan carpenter
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] tty: nozomi: Fix a resource leak in an error handling function
2021-05-09 17:22 [PATCH] tty: nozomi: Fix a resource leak in an error handling function Christophe JAILLET
2021-05-10 6:35 ` Dan Carpenter
@ 2021-05-10 9:51 ` Jiri Slaby
1 sibling, 0 replies; 3+ messages in thread
From: Jiri Slaby @ 2021-05-10 9:51 UTC (permalink / raw)
To: Christophe JAILLET, gregkh, akpm, stefani; +Cc: linux-kernel, kernel-janitors
On 09. 05. 21, 19:22, Christophe JAILLET wrote:
> A 'request_irq()' call is not balanced by a corresponding 'free_irq()' in
> the error handling path, as already done in the remove function.
>
> Add it.
>
> Fixes: 9842c38e9176 ("kfifo: fix warn_unused_result")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
> ---
> I also wonder if the loop above is correct. The 'i < MAX_PORT' looks really
> spurious to me.
> 'tty_port_destroy' can be called twice for the same entry (once before
> branching in the error handling path, and once in here) and
> 'tty_unregister_device'/'tty_port_destroy' will be called on entries
> that have not been 'tty_port_init'ed or 'tty_port_register_device'd.
> I don't know if it may be an issue.
Yes. The fail path handling is very broken there. Both the code of
err_free_tty label, and of the err_free_kfifo label. The loops should
have been _something_ (I didn't invest much thinking into it, so it's
likely wrong) like:
for (i--; i--; ) {
...
}
> ---
> drivers/tty/nozomi.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c
> index 9a2d78ace49b..b270e137ef9b 100644
> --- a/drivers/tty/nozomi.c
> +++ b/drivers/tty/nozomi.c
> @@ -1420,6 +1420,7 @@ static int nozomi_card_init(struct pci_dev *pdev,
> tty_unregister_device(ntty_driver, dc->index_start + i);
> tty_port_destroy(&dc->port[i].port);
> }
> + free_irq(pdev->irq, dc);
> err_free_kfifo:
> for (i = 0; i < MAX_PORT; i++)
> kfifo_free(&dc->port[i].fifo_ul);
>
thanks,
--
js
suse labs
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-05-10 6:35 ` Dan Carpenter
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