[PATCH] EDAC/versalnet: fix memory leak on device registration failure

[PATCH] EDAC/versalnet: fix memory leak on device registration failure

[Guangshuo Li]

init_one_mc() allocates dev with kzalloc() and registers it with
device_register(). If device_register() fails, the device has already
been initialized and holds its initial device reference.

The current error path eventually frees dev directly with kfree().
This bypasses the device release path and can leak driver-core
resources associated with the initialized device. The existing
versal_edac_release() callback is responsible for freeing dev once the
device reference reaches zero.

Call put_device() when device_register() fails so the initialized
device reference is dropped and versal_edac_release() performs the
proper cleanup. Return after freeing mci to avoid falling through to
the direct kfree() path, which remains necessary for failures that
occur before device_register() is called.

The issue was identified by a static analysis tool I developed and
confirmed by manual review.

Fixes: d5fe2fec6c40 ("EDAC: Add a driver for the AMD Versal NET DDR controller")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/edac/versalnet_edac.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/edac/versalnet_edac.c b/drivers/edac/versalnet_edac.c
index 3a06b41c1d84..db3bf5a1345b 100644
--- a/drivers/edac/versalnet_edac.c
+++ b/drivers/edac/versalnet_edac.c
@@ -829,8 +829,10 @@ static int init_one_mc(struct mc_priv *priv, struct platform_device *pdev, int i
 	dev->release = versal_edac_release;
 
 	rc = device_register(dev);
-	if (rc)
+	if (rc) {
+		put_device(dev);
 		goto err_mc_free;
+	}
 
 	mci->pdev = dev;
 	mc_init(mci, dev);
@@ -852,9 +854,9 @@ static int init_one_mc(struct mc_priv *priv, struct platform_device *pdev, int i
 	device_unregister(mci->pdev);
 err_mc_free:
 	edac_mc_free(mci);
+	return rc;
 err_dev_free:
 	kfree(dev);
-
 	return rc;
 }
 
-- 
2.43.0

Re: [PATCH] EDAC/versalnet: fix memory leak on device registration failure

[krzk]

On Sun, 20 Sep 2026 13:55:19 +0800, Guangshuo Li wrote:
> init_one_mc() allocates dev with kzalloc() and registers it with
> device_register(). If device_register() fails, the device has already
> been initialized and holds its initial device reference.
> 
> The current error path eventually frees dev directly with kfree().
> This bypasses the device release path and can leak driver-core
> resources associated with the initialized device. The existing
> versal_edac_release() callback is responsible for freeing dev once the
> device reference reaches zero.
> 
> Call put_device() when device_register() fails so the initialized
> device reference is dropped and versal_edac_release() performs the
> proper cleanup. Return after freeing mci to avoid falling through to
> the direct kfree() path, which remains necessary for failures that
> occur before device_register() is called.
> 
> The issue was identified by a static analysis tool I developed and
> confirmed by manual review.
> 
> Fixes: d5fe2fec6c40 ("EDAC: Add a driver for the AMD Versal NET DDR controller")
> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
> ---
>  drivers/edac/versalnet_edac.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 


You sent multiple independent patches, to multiple independent
subsystems. The amount of these patches clearly suggest this was
AI generated and most likely not tested.

More importantly, you sent all this work without properly organizing
relevant patches into patchsets. This makes reviewing difficult
and might cause multiple reviewers to address the same issue.
Replying to the entire set is impossible and requires handling each
patch independently, instead of applying or discarding the set.
Maintainers also won't see the bigger picture of your work. Quite
worrying.

This is on the verge of hostile patch: bomb us with so many
contributions, we won't be able to handle them in efficient manner,
like responding ONCE to ask you to slow down.  Considering all this
is untested and LLM generated, I have even more doubts whether this
should be considered for review.

Please read kernel documentation BEFORE posting more work. It will
explain you how to identify subsystems, how to organize your work per
subsystem, how to document usage of LLM and how what you should not
do if this was posted in a good faith.

Best regards,
Krzysztof

Re: [PATCH] EDAC/versalnet: fix memory leak on device registration failure

[Guangshuo Li]

Hi Krzysztof,

Thank you for your feedback.

On Mon, 21 Sept 2026 at 23:11, <krzk@kernel.org> wrote:
>
>
> On Sun, 20 Sep 2026 13:55:19 +0800, Guangshuo Li wrote:
> > init_one_mc() allocates dev with kzalloc() and registers it with
> > device_register(). If device_register() fails, the device has already
> > been initialized and holds its initial device reference.
> >
> > The current error path eventually frees dev directly with kfree().
> > This bypasses the device release path and can leak driver-core
> > resources associated with the initialized device. The existing
> > versal_edac_release() callback is responsible for freeing dev once the
> > device reference reaches zero.
> >
> > Call put_device() when device_register() fails so the initialized
> > device reference is dropped and versal_edac_release() performs the
> > proper cleanup. Return after freeing mci to avoid falling through to
> > the direct kfree() path, which remains necessary for failures that
> > occur before device_register() is called.
> >
> > The issue was identified by a static analysis tool I developed and
> > confirmed by manual review.
> >
> > Fixes: d5fe2fec6c40 ("EDAC: Add a driver for the AMD Versal NET DDR controller")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
> > ---
> >  drivers/edac/versalnet_edac.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> >
>
>
> You sent multiple independent patches, to multiple independent
> subsystems. The amount of these patches clearly suggest this was
> AI generated and most likely not tested.
>
> More importantly, you sent all this work without properly organizing
> relevant patches into patchsets. This makes reviewing difficult
> and might cause multiple reviewers to address the same issue.
> Replying to the entire set is impossible and requires handling each
> patch independently, instead of applying or discarding the set.
> Maintainers also won't see the bigger picture of your work. Quite
> worrying.
>
> This is on the verge of hostile patch: bomb us with so many
> contributions, we won't be able to handle them in efficient manner,
> like responding ONCE to ask you to slow down.  Considering all this
> is untested and LLM generated, I have even more doubts whether this
> should be considered for review.
>
> Please read kernel documentation BEFORE posting more work. It will
> explain you how to identify subsystems, how to organize your work per
> subsystem, how to document usage of LLM and how what you should not
> do if this was posted in a good faith.
>
> Best regards,
> Krzysztof
>
>
>

I would like to clarify that these patches were manually reviewed and
audited by us; they were not simply generated and submitted by an LLM.
However, I understand why the recent submission pattern may have given
that impression. We sent too many patches in a short period of time,
and we also failed to respond to some discussions in a timely manner,
which made the situation look worse.

Many of the recent patches, especially the v2 revisions, are
corrections and improvements based on previous review feedback rather
than completely new untested changes. That said, we recognize that the
way we submitted them increased the burden on maintainers and
reviewers.

We apologize for the pressure this caused to the community. We will be
more careful about organizing patches by subsystem, preparing proper
patchsets, and following the kernel contribution guidelines before
sending future work.

Thank you again for pointing this out.

Best regards,
Guangshuo

Re: [PATCH] EDAC/versalnet: fix memory leak on device registration failure

[krzk]

On Sun, 20 Sep 2026 13:55:19 +0800, Guangshuo Li wrote:
> init_one_mc() allocates dev with kzalloc() and registers it with
> device_register(). If device_register() fails, the device has already
> been initialized and holds its initial device reference.
> 
> The current error path eventually frees dev directly with kfree().
> This bypasses the device release path and can leak driver-core
> resources associated with the initialized device. The existing
> versal_edac_release() callback is responsible for freeing dev once the
> device reference reaches zero.
> 
> Call put_device() when device_register() fails so the initialized
> device reference is dropped and versal_edac_release() performs the
> proper cleanup. Return after freeing mci to avoid falling through to
> the direct kfree() path, which remains necessary for failures that
> occur before device_register() is called.
> 
> The issue was identified by a static analysis tool I developed and
> confirmed by manual review.
> 
> Fixes: d5fe2fec6c40 ("EDAC: Add a driver for the AMD Versal NET DDR controller")
> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
> ---
>  drivers/edac/versalnet_edac.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 


You sent multiple independent patches, to multiple independent
subsystems. The amount of these patches clearly suggest this was
AI generated and most likely not tested.

More importantly, you sent all this work without properly organizing
relevant patches into patchsets. This makes reviewing difficult
and might cause multiple reviewers to address the same issue.
Replying to the entire set is impossible and requires handling each
patch independently, instead of applying or discarding the set.
Maintainers also won't see the bigger picture of your work. Quite
worrying.

This is on the verge of hostile patch: bomb us with so many
contributions, we won't be able to handle them in efficient manner,
like responding ONCE to ask you to slow down.  Considering all this
is untested and LLM generated, I have even more doubts whether this
should be considered for review.

Please read kernel documentation BEFORE posting more work. It will
explain you how to identify subsystems, how to organize your work per
subsystem, how to document usage of LLM and how what you should not
do if this was posted in a good faith.

Best regards,
Krzysztof

Re: [PATCH] EDAC/versalnet: fix memory leak on device registration failure

[Shubhrajyoti Datta]

On Sun, Sep 20, 2026 at 11:25 AM Guangshuo Li <lgs201920130244@gmail.com> wrote:
>
> init_one_mc() allocates dev with kzalloc() and registers it with
> device_register(). If device_register() fails, the device has already
> been initialized and holds its initial device reference.
>
> The current error path eventually frees dev directly with kfree().
> This bypasses the device release path and can leak driver-core
> resources associated with the initialized device. The existing
> versal_edac_release() callback is responsible for freeing dev once the
> device reference reaches zero.
>
> Call put_device() when device_register() fails so the initialized
> device reference is dropped and versal_edac_release() performs the
> proper cleanup. Return after freeing mci to avoid falling through to
> the direct kfree() path, which remains necessary for failures that
> occur before device_register() is called.
>
> The issue was identified by a static analysis tool I developed and
> confirmed by manual review.
>
> Fixes: d5fe2fec6c40 ("EDAC: Add a driver for the AMD Versal NET DDR controller")
> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
> ---
>  drivers/edac/versalnet_edac.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/edac/versalnet_edac.c b/drivers/edac/versalnet_edac.c
> index 3a06b41c1d84..db3bf5a1345b 100644
> --- a/drivers/edac/versalnet_edac.c
> +++ b/drivers/edac/versalnet_edac.c
> @@ -829,8 +829,10 @@ static int init_one_mc(struct mc_priv *priv, struct platform_device *pdev, int i
>         dev->release = versal_edac_release;
>
>         rc = device_register(dev);
> -       if (rc)
> +       if (rc) {
> +               put_device(dev);
>                 goto err_mc_free;
> +       }

There was a comment earlier from sashiko
 failure path calls put_device() with dev->init_name still pointing at a stack
buffer before device_add() copies it. That's unsafe in
principle (dev_name() would follow init_name)
>
>         mci->pdev = dev;
>         mc_init(mci, dev);
> @@ -852,9 +854,9 @@ static int init_one_mc(struct mc_priv *priv, struct platform_device *pdev, int i
>         device_unregister(mci->pdev);
>  err_mc_free:
>         edac_mc_free(mci);
> +       return rc;
>  err_dev_free:
>         kfree(dev);
> -
>         return rc;
>  }
>
> --
> 2.43.0
>
>

Re: [PATCH] EDAC/versalnet: fix memory leak on device registration failure

[Guangshuo Li]

Hi Shubhrajyoti,

Thanks for pointing that out.

On Wed, 23 Sept 2026 at 23:03, Shubhrajyoti Datta
<shubhrajyoti.datta@gmail.com> wrote:
>
> On Sun, Sep 20, 2026 at 11:25 AM Guangshuo Li <lgs201920130244@gmail.com> wrote:
> >
> > init_one_mc() allocates dev with kzalloc() and registers it with
> > device_register(). If device_register() fails, the device has already
> > been initialized and holds its initial device reference.
> >
> > The current error path eventually frees dev directly with kfree().
> > This bypasses the device release path and can leak driver-core
> > resources associated with the initialized device. The existing
> > versal_edac_release() callback is responsible for freeing dev once the
> > device reference reaches zero.
> >
> > Call put_device() when device_register() fails so the initialized
> > device reference is dropped and versal_edac_release() performs the
> > proper cleanup. Return after freeing mci to avoid falling through to
> > the direct kfree() path, which remains necessary for failures that
> > occur before device_register() is called.
> >
> > The issue was identified by a static analysis tool I developed and
> > confirmed by manual review.
> >
> > Fixes: d5fe2fec6c40 ("EDAC: Add a driver for the AMD Versal NET DDR controller")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
> > ---
> >  drivers/edac/versalnet_edac.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/edac/versalnet_edac.c b/drivers/edac/versalnet_edac.c
> > index 3a06b41c1d84..db3bf5a1345b 100644
> > --- a/drivers/edac/versalnet_edac.c
> > +++ b/drivers/edac/versalnet_edac.c
> > @@ -829,8 +829,10 @@ static int init_one_mc(struct mc_priv *priv, struct platform_device *pdev, int i
> >         dev->release = versal_edac_release;
> >
> >         rc = device_register(dev);
> > -       if (rc)
> > +       if (rc) {
> > +               put_device(dev);
> >                 goto err_mc_free;
> > +       }
>
> There was a comment earlier from sashiko
>  failure path calls put_device() with dev->init_name still pointing at a stack
> buffer before device_add() copies it. That's unsafe in
> principle (dev_name() would follow init_name)
> >
> >         mci->pdev = dev;
> >         mc_init(mci, dev);
> > @@ -852,9 +854,9 @@ static int init_one_mc(struct mc_priv *priv, struct platform_device *pdev, int i
> >         device_unregister(mci->pdev);
> >  err_mc_free:
> >         edac_mc_free(mci);
> > +       return rc;
> >  err_dev_free:
> >         kfree(dev);
> > -
> >         return rc;
> >  }
> >
> > --
> > 2.43.0
> >
> >

Would splitting device_register() into device_initialize(), dev_set_name(),
and device_add() be a reasonable way to handle this? For example:

diff --git a/drivers/edac/versalnet_edac.c b/drivers/edac/versalnet_edac.c
--- a/drivers/edac/versalnet_edac.c
+++ b/drivers/edac/versalnet_edac.c
@@ -64,7 +64,6 @@
 #define XDDR5_BUS_WIDTH_64 0
 #define XDDR5_BUS_WIDTH_32 1
 #define XDDR5_BUS_WIDTH_16 2
-#define MC_NAME_LEN 32

 static int init_one_mc(struct mc_priv *priv, struct platform_device
*pdev, int i)
 {
@@ -730,7 +729,6 @@ static int init_one_mc(struct mc_priv *priv,
struct platform_device *pdev, int i)
  u32 num_chans, rank, dwidth, config;
  struct edac_mc_layer layers[2];
  struct mem_ctl_info *mci;
- char name[MC_NAME_LEN];
  struct device *dev;
  enum dev_type dt;
  int rc;
@@ -773,13 +771,17 @@ static int init_one_mc(struct mc_priv *priv,
struct platform_device *pdev, int i)
  goto err_dev_free;
  }

- sprintf(name, "versal-net-ddrmc5-edac-%d", i);
-
- dev->init_name = name;
+ device_initialize(dev);
  dev->release = versal_edac_release;

- rc = device_register(dev);
+ rc = dev_set_name(dev, "versal-net-ddrmc5-edac-%d", i);
+ if (rc)
+ goto err_mc_free;
+
+ rc = device_add(dev);
  if (rc)
  goto err_mc_free;

@@ -800,10 +802,13 @@ static int init_one_mc(struct mc_priv *priv,
struct platform_device *pdev, int i)

 err_unreg:
  device_unregister(mci->pdev);
+ edac_mc_free(mci);
+ return rc;
 err_mc_free:
  edac_mc_free(mci);
+ put_device(dev);
+ return rc;
 err_dev_free:
  kfree(dev);

  return rc;
 }

This avoids keeping dev->init_name pointing at stack storage and uses
put_device() only after the device has been initialized. Would this look
reasonable to you? If this looks good to you, I’ll send v2 with this approach.

Thanks,
Guangshuo

Re: [PATCH] EDAC/versalnet: fix memory leak on device registration failure

[Shubhrajyoti Datta]

On Thu, Sep 24, 2026 at 7:45 PM Guangshuo Li <lgs201920130244@gmail.com> wrote:
>
> Hi Shubhrajyoti,
>
> Thanks for pointing that out.
>
> On Wed, 23 Sept 2026 at 23:03, Shubhrajyoti Datta
> <shubhrajyoti.datta@gmail.com> wrote:
> >
> > On Sun, Sep 20, 2026 at 11:25 AM Guangshuo Li <lgs201920130244@gmail.com> wrote:
> > >
> > > init_one_mc() allocates dev with kzalloc() and registers it with
> > > device_register(). If device_register() fails, the device has already
> > > been initialized and holds its initial device reference.
> > >
> > > The current error path eventually frees dev directly with kfree().
> > > This bypasses the device release path and can leak driver-core
> > > resources associated with the initialized device. The existing
> > > versal_edac_release() callback is responsible for freeing dev once the
> > > device reference reaches zero.
> > >
> > > Call put_device() when device_register() fails so the initialized
> > > device reference is dropped and versal_edac_release() performs the
> > > proper cleanup. Return after freeing mci to avoid falling through to
> > > the direct kfree() path, which remains necessary for failures that
> > > occur before device_register() is called.
> > >
> > > The issue was identified by a static analysis tool I developed and
> > > confirmed by manual review.
> > >
> > > Fixes: d5fe2fec6c40 ("EDAC: Add a driver for the AMD Versal NET DDR controller")
> > > Cc: stable@vger.kernel.org
> > > Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
> > > ---
> > >  drivers/edac/versalnet_edac.c | 6 ++++--
> > >  1 file changed, 4 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/edac/versalnet_edac.c b/drivers/edac/versalnet_edac.c
> > > index 3a06b41c1d84..db3bf5a1345b 100644
> > > --- a/drivers/edac/versalnet_edac.c
> > > +++ b/drivers/edac/versalnet_edac.c
> > > @@ -829,8 +829,10 @@ static int init_one_mc(struct mc_priv *priv, struct platform_device *pdev, int i
> > >         dev->release = versal_edac_release;
> > >
> > >         rc = device_register(dev);
> > > -       if (rc)
> > > +       if (rc) {
> > > +               put_device(dev);
> > >                 goto err_mc_free;
> > > +       }
> >
> > There was a comment earlier from sashiko
> >  failure path calls put_device() with dev->init_name still pointing at a stack
> > buffer before device_add() copies it. That's unsafe in
> > principle (dev_name() would follow init_name)
> > >
> > >         mci->pdev = dev;
> > >         mc_init(mci, dev);
> > > @@ -852,9 +854,9 @@ static int init_one_mc(struct mc_priv *priv, struct platform_device *pdev, int i
> > >         device_unregister(mci->pdev);
> > >  err_mc_free:
> > >         edac_mc_free(mci);
> > > +       return rc;
> > >  err_dev_free:
> > >         kfree(dev);
> > > -
> > >         return rc;
> > >  }
> > >
> > > --
> > > 2.43.0
> > >
> > >
>
> Would splitting device_register() into device_initialize(), dev_set_name(),
> and device_add() be a reasonable way to handle this? For example:
>
> diff --git a/drivers/edac/versalnet_edac.c b/drivers/edac/versalnet_edac.c
> --- a/drivers/edac/versalnet_edac.c
> +++ b/drivers/edac/versalnet_edac.c
> @@ -64,7 +64,6 @@
>  #define XDDR5_BUS_WIDTH_64 0
>  #define XDDR5_BUS_WIDTH_32 1
>  #define XDDR5_BUS_WIDTH_16 2
> -#define MC_NAME_LEN 32
>
>  static int init_one_mc(struct mc_priv *priv, struct platform_device
> *pdev, int i)
>  {
> @@ -730,7 +729,6 @@ static int init_one_mc(struct mc_priv *priv,
> struct platform_device *pdev, int i)
>   u32 num_chans, rank, dwidth, config;
>   struct edac_mc_layer layers[2];
>   struct mem_ctl_info *mci;
> - char name[MC_NAME_LEN];
>   struct device *dev;
>   enum dev_type dt;
>   int rc;
> @@ -773,13 +771,17 @@ static int init_one_mc(struct mc_priv *priv,
> struct platform_device *pdev, int i)
>   goto err_dev_free;
>   }
>
> - sprintf(name, "versal-net-ddrmc5-edac-%d", i);
> -
> - dev->init_name = name;
> + device_initialize(dev);
>   dev->release = versal_edac_release;
>
> - rc = device_register(dev);
> + rc = dev_set_name(dev, "versal-net-ddrmc5-edac-%d", i);
> + if (rc)
> + goto err_mc_free;
> +
> + rc = device_add(dev);
>   if (rc)
>   goto err_mc_free;
>
> @@ -800,10 +802,13 @@ static int init_one_mc(struct mc_priv *priv,
> struct platform_device *pdev, int i)
>
>  err_unreg:
>   device_unregister(mci->pdev);
> + edac_mc_free(mci);
> + return rc;
>  err_mc_free:
>   edac_mc_free(mci);
> + put_device(dev);
> + return rc;
>  err_dev_free:
>   kfree(dev);
>
>   return rc;
>  }
>
> This avoids keeping dev->init_name pointing at stack storage and uses
> put_device() only after the device has been initialized. Would this look
> reasonable to you? If this looks good to you, I’ll send v2 with this approach.

This is already addressed in the ongoing patch series:

https://lore.kernel.org/all/20260724171945.2812749-5-shubhrajyoti.datta@amd.com/

Please have a look and let me know if you have any concerns.
>
> Thanks,
> Guangshuo