* [PATCH] HV: hv_balloon: fix memory leak with using debugfs_lookup()
@ 2023-02-02 14:09 Greg Kroah-Hartman
2023-02-03 3:56 ` Michael Kelley (LINUX)
0 siblings, 1 reply; 3+ messages in thread
From: Greg Kroah-Hartman @ 2023-02-02 14:09 UTC (permalink / raw)
To: linux-hyperv
Cc: Greg Kroah-Hartman, K. Y. Srinivasan, Haiyang Zhang, Wei Liu,
Dexuan Cui, linux-kernel
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: linux-hyperv@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/hv/hv_balloon.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index cbe43e2567a7..64ac5bdee3a6 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -1963,7 +1963,7 @@ static void hv_balloon_debugfs_init(struct hv_dynmem_device *b)
static void hv_balloon_debugfs_exit(struct hv_dynmem_device *b)
{
- debugfs_remove(debugfs_lookup("hv-balloon", NULL));
+ debugfs_lookup_and_remove("hv-balloon", NULL);
}
#else
--
2.39.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* RE: [PATCH] HV: hv_balloon: fix memory leak with using debugfs_lookup()
2023-02-02 14:09 [PATCH] HV: hv_balloon: fix memory leak with using debugfs_lookup() Greg Kroah-Hartman
@ 2023-02-03 3:56 ` Michael Kelley (LINUX)
2023-02-03 6:44 ` Greg Kroah-Hartman
0 siblings, 1 reply; 3+ messages in thread
From: Michael Kelley (LINUX) @ 2023-02-03 3:56 UTC (permalink / raw)
To: Greg Kroah-Hartman, linux-hyperv@vger.kernel.org
Cc: KY Srinivasan, Haiyang Zhang, Wei Liu, Dexuan Cui,
linux-kernel@vger.kernel.org
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Sent: Thursday, February 2, 2023 6:09 AM
>
> When calling debugfs_lookup() the result must have dput() called on it,
> otherwise the memory will leak over time. To make things simpler, just
> call debugfs_lookup_and_remove() instead which handles all of the logic
> at once.
>
> Cc: "K. Y. Srinivasan" <kys@microsoft.com>
> Cc: Haiyang Zhang <haiyangz@microsoft.com>
> Cc: Wei Liu <wei.liu@kernel.org>
> Cc: Dexuan Cui <decui@microsoft.com>
> Cc: linux-hyperv@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a Fixes: tag? This hv_balloon debugfs code was added in v6.0,
And I see that debugfs_lookup_and_remove() was also added in v6.0.
Fixes: d180e0a1be6c ("Drivers: hv: Create debugfs file with hyper-v balloon usage information")
> ---
> drivers/hv/hv_balloon.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
> index cbe43e2567a7..64ac5bdee3a6 100644
> --- a/drivers/hv/hv_balloon.c
> +++ b/drivers/hv/hv_balloon.c
> @@ -1963,7 +1963,7 @@ static void hv_balloon_debugfs_init(struct hv_dynmem_device *b)
>
> static void hv_balloon_debugfs_exit(struct hv_dynmem_device *b)
> {
> - debugfs_remove(debugfs_lookup("hv-balloon", NULL));
> + debugfs_lookup_and_remove("hv-balloon", NULL);
> }
>
> #else
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] HV: hv_balloon: fix memory leak with using debugfs_lookup()
2023-02-03 3:56 ` Michael Kelley (LINUX)
@ 2023-02-03 6:44 ` Greg Kroah-Hartman
0 siblings, 0 replies; 3+ messages in thread
From: Greg Kroah-Hartman @ 2023-02-03 6:44 UTC (permalink / raw)
To: Michael Kelley (LINUX)
Cc: linux-hyperv@vger.kernel.org, KY Srinivasan, Haiyang Zhang,
Wei Liu, Dexuan Cui, linux-kernel@vger.kernel.org
On Fri, Feb 03, 2023 at 03:56:06AM +0000, Michael Kelley (LINUX) wrote:
> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Sent: Thursday, February 2, 2023 6:09 AM
>
> >
> > When calling debugfs_lookup() the result must have dput() called on it,
> > otherwise the memory will leak over time. To make things simpler, just
> > call debugfs_lookup_and_remove() instead which handles all of the logic
> > at once.
> >
> > Cc: "K. Y. Srinivasan" <kys@microsoft.com>
> > Cc: Haiyang Zhang <haiyangz@microsoft.com>
> > Cc: Wei Liu <wei.liu@kernel.org>
> > Cc: Dexuan Cui <decui@microsoft.com>
> > Cc: linux-hyperv@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
> Add a Fixes: tag? This hv_balloon debugfs code was added in v6.0,
> And I see that debugfs_lookup_and_remove() was also added in v6.0.
>
> Fixes: d180e0a1be6c ("Drivers: hv: Create debugfs file with hyper-v balloon usage information")
Will do, thanks.
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-02-02 14:09 [PATCH] HV: hv_balloon: fix memory leak with using debugfs_lookup() Greg Kroah-Hartman
2023-02-03 3:56 ` Michael Kelley (LINUX)
2023-02-03 6:44 ` Greg Kroah-Hartman
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