* [PATCH 1/1] USB: inode.c: fix unbalanced spin_lock in ep0_write
@ 2015-12-11 19:56 David Eccher
2015-12-11 20:11 ` Al Viro
2015-12-11 20:57 ` Sergei Shtylyov
0 siblings, 2 replies; 4+ messages in thread
From: David Eccher @ 2015-12-11 19:56 UTC (permalink / raw)
To: Felipe Balbi
Cc: Greg Kroah-Hartman, Al Viro, linux-usb, linux-kernel,
David Eccher
Fix bad unlock balance: ep0_write enter with the locks locked from inode.c:1769,
hence it must exit with spinlock held to avoid double unlock in dev_config.
Signed-off-by: David Eccher <d.eccher@gmail.com>
---
drivers/usb/gadget/legacy/inode.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index f454c7a..b968c25 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -1144,6 +1144,7 @@ ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
} else
retval = len;
+ spin_lock_irq (&dev->lock);
return retval;
}
--
1.8.1.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/1] USB: inode.c: fix unbalanced spin_lock in ep0_write
2015-12-11 19:56 [PATCH 1/1] USB: inode.c: fix unbalanced spin_lock in ep0_write David Eccher
@ 2015-12-11 20:11 ` Al Viro
2015-12-11 21:12 ` David Eccher
2015-12-11 20:57 ` Sergei Shtylyov
1 sibling, 1 reply; 4+ messages in thread
From: Al Viro @ 2015-12-11 20:11 UTC (permalink / raw)
To: David Eccher; +Cc: Felipe Balbi, Greg Kroah-Hartman, linux-usb, linux-kernel
On Fri, Dec 11, 2015 at 08:56:26PM +0100, David Eccher wrote:
> Fix bad unlock balance: ep0_write enter with the locks locked from inode.c:1769,
> hence it must exit with spinlock held to avoid double unlock in dev_config.
*Ugh*
Just take that spinlock before the if (retval < 0) and don't drop it after
clear_req(), then...
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 1/1] USB: inode.c: fix unbalanced spin_lock in ep0_write
2015-12-11 19:56 [PATCH 1/1] USB: inode.c: fix unbalanced spin_lock in ep0_write David Eccher
2015-12-11 20:11 ` Al Viro
@ 2015-12-11 20:57 ` Sergei Shtylyov
1 sibling, 0 replies; 4+ messages in thread
From: Sergei Shtylyov @ 2015-12-11 20:57 UTC (permalink / raw)
To: David Eccher, Felipe Balbi
Cc: Greg Kroah-Hartman, Al Viro, linux-usb, linux-kernel
Hello.
On 12/11/2015 10:56 PM, David Eccher wrote:
> Fix bad unlock balance: ep0_write enter with the locks locked from inode.c:1769,
> hence it must exit with spinlock held to avoid double unlock in dev_config.
>
> Signed-off-by: David Eccher <d.eccher@gmail.com>
> ---
> drivers/usb/gadget/legacy/inode.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
> index f454c7a..b968c25 100644
> --- a/drivers/usb/gadget/legacy/inode.c
> +++ b/drivers/usb/gadget/legacy/inode.c
> @@ -1144,6 +1144,7 @@ ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
> } else
> retval = len;
>
> + spin_lock_irq (&dev->lock);
I guess you hadn't run the patch thru scripts/checkpatch.pl?
MBR, Sergei
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 1/1] USB: inode.c: fix unbalanced spin_lock in ep0_write
2015-12-11 20:11 ` Al Viro
@ 2015-12-11 21:12 ` David Eccher
0 siblings, 0 replies; 4+ messages in thread
From: David Eccher @ 2015-12-11 21:12 UTC (permalink / raw)
To: Al Viro; +Cc: Felipe Balbi, Greg Kroah-Hartman, linux-usb, linux-kernel
On Fri, Dec 11, 2015 at 9:11 PM, Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> On Fri, Dec 11, 2015 at 08:56:26PM +0100, David Eccher wrote:
> > Fix bad unlock balance: ep0_write enter with the locks locked from inode.c:1769,
> > hence it must exit with spinlock held to avoid double unlock in dev_config.
>
> *Ugh*
>
> Just take that spinlock before the if (retval < 0) and don't drop it after
> clear_req(), then...
Oh, yeah good point, I'll send a v2...and test the patch thru
checkpatch.pl, sorry
--
David Eccher
^ permalink raw reply [flat|nested] 4+ messages in thread
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2015-12-11 19:56 [PATCH 1/1] USB: inode.c: fix unbalanced spin_lock in ep0_write David Eccher
2015-12-11 20:11 ` Al Viro
2015-12-11 21:12 ` David Eccher
2015-12-11 20:57 ` Sergei Shtylyov
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