[PATCH] drivers core: Fix oops when driver probe fails

[PATCH] drivers core: Fix oops when driver probe fails

[Filip Schauer]

[-- Attachment #1: Type: text/plain, Size: 1875 bytes --]

dma_range_map is freed to early, which might cause an oops when
a driver probe fails.
 Call trace:
  is_free_buddy_page+0xe4/0x1d4
  __free_pages+0x2c/0x88
  dma_free_contiguous+0x64/0x80
  dma_direct_free+0x38/0xb4
  dma_free_attrs+0x88/0xa0
  dmam_release+0x28/0x34
  release_nodes+0x78/0x8c
  devres_release_all+0xa8/0x110
  really_probe+0x118/0x2d0
  __driver_probe_device+0xc8/0xe0
  driver_probe_device+0x54/0xec
  __driver_attach+0xe0/0xf0
  bus_for_each_dev+0x7c/0xc8
  driver_attach+0x30/0x3c
  bus_add_driver+0x17c/0x1c4
  driver_register+0xc0/0xf8
  __platform_driver_register+0x34/0x40
  ...

This issue is introduced by commit d0243bbd5dd3 ("drivers core:
Free dma_range_map when driver probe failed"). It frees
dma_range_map before the call to devres_release_all, which is too
early. The solution is to free dma_range_map only after
devres_release_all.

Fixes: d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe
failed")
Signed-off-by: Filip Schauer <filip@mg6.at>
---
 drivers/base/dd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index daeb9b5763ae..437cd61343b2 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -653,8 +653,6 @@ static int really_probe(struct device *dev, struct
device_driver *drv)
 	else if (drv->remove)
 		drv->remove(dev);
 probe_failed:
- kfree(dev->dma_range_map);
- dev->dma_range_map = NULL;
 	if (dev->bus)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
@@ -662,6 +660,8 @@ static int really_probe(struct device *dev, struct
device_driver *drv)
 	device_links_no_driver(dev);
 	devres_release_all(dev);
 	arch_teardown_dma_ops(dev);
+ kfree(dev->dma_range_map);
+ dev->dma_range_map = NULL;
 	driver_sysfs_remove(dev);
 	dev->driver = NULL;
 	dev_set_drvdata(dev, NULL);
-- 
2.25.1


[-- Attachment #2: unknown --]
[-- Type: text/x-diff, Size: 1875 bytes --]

dma_range_map is freed to early, which might cause an oops when
a driver probe fails.
 Call trace:
  is_free_buddy_page+0xe4/0x1d4
  __free_pages+0x2c/0x88
  dma_free_contiguous+0x64/0x80
  dma_direct_free+0x38/0xb4
  dma_free_attrs+0x88/0xa0
  dmam_release+0x28/0x34
  release_nodes+0x78/0x8c
  devres_release_all+0xa8/0x110
  really_probe+0x118/0x2d0
  __driver_probe_device+0xc8/0xe0
  driver_probe_device+0x54/0xec
  __driver_attach+0xe0/0xf0
  bus_for_each_dev+0x7c/0xc8
  driver_attach+0x30/0x3c
  bus_add_driver+0x17c/0x1c4
  driver_register+0xc0/0xf8
  __platform_driver_register+0x34/0x40
  ...

This issue is introduced by commit d0243bbd5dd3 ("drivers core:
Free dma_range_map when driver probe failed"). It frees
dma_range_map before the call to devres_release_all, which is too
early. The solution is to free dma_range_map only after
devres_release_all.

Fixes: d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed")
Signed-off-by: Filip Schauer <filip@mg6.at>
---
 drivers/base/dd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index daeb9b5763ae..437cd61343b2 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -653,8 +653,6 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	else if (drv->remove)
 		drv->remove(dev);
 probe_failed:
-	kfree(dev->dma_range_map);
-	dev->dma_range_map = NULL;
 	if (dev->bus)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
@@ -662,6 +660,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	device_links_no_driver(dev);
 	devres_release_all(dev);
 	arch_teardown_dma_ops(dev);
+	kfree(dev->dma_range_map);
+	dev->dma_range_map = NULL;
 	driver_sysfs_remove(dev);
 	dev->driver = NULL;
 	dev_set_drvdata(dev, NULL);
-- 
2.25.1

Re: [PATCH] drivers core: Fix oops when driver probe fails

[Greg KH]

On Tue, Jul 27, 2021 at 12:40:35PM +0200, Filip Schauer wrote:
> dma_range_map is freed to early, which might cause an oops when
> a driver probe fails.
>  Call trace:
>   is_free_buddy_page+0xe4/0x1d4
>   __free_pages+0x2c/0x88
>   dma_free_contiguous+0x64/0x80
>   dma_direct_free+0x38/0xb4
>   dma_free_attrs+0x88/0xa0
>   dmam_release+0x28/0x34
>   release_nodes+0x78/0x8c
>   devres_release_all+0xa8/0x110
>   really_probe+0x118/0x2d0
>   __driver_probe_device+0xc8/0xe0
>   driver_probe_device+0x54/0xec
>   __driver_attach+0xe0/0xf0
>   bus_for_each_dev+0x7c/0xc8
>   driver_attach+0x30/0x3c
>   bus_add_driver+0x17c/0x1c4
>   driver_register+0xc0/0xf8
>   __platform_driver_register+0x34/0x40
>   ...
> 
> This issue is introduced by commit d0243bbd5dd3 ("drivers core:
> Free dma_range_map when driver probe failed"). It frees
> dma_range_map before the call to devres_release_all, which is too
> early. The solution is to free dma_range_map only after
> devres_release_all.
> 
> Fixes: d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe
> failed")
> Signed-off-by: Filip Schauer <filip@mg6.at>
> ---
>  drivers/base/dd.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index daeb9b5763ae..437cd61343b2 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -653,8 +653,6 @@ static int really_probe(struct device *dev, struct
> device_driver *drv)
>  	else if (drv->remove)
>  		drv->remove(dev);
>  probe_failed:
> - kfree(dev->dma_range_map);
> - dev->dma_range_map = NULL;
>  	if (dev->bus)
>  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
>  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
> @@ -662,6 +660,8 @@ static int really_probe(struct device *dev, struct
> device_driver *drv)
>  	device_links_no_driver(dev);
>  	devres_release_all(dev);
>  	arch_teardown_dma_ops(dev);
> + kfree(dev->dma_range_map);
> + dev->dma_range_map = NULL;
>  	driver_sysfs_remove(dev);
>  	dev->driver = NULL;
>  	dev_set_drvdata(dev, NULL);
> -- 
> 2.25.1
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- Your patch is malformed (tabs converted to spaces, linewrapped, etc.)
  and can not be applied.  Please read the file,
  Documentation/email-clients.txt in order to fix this.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot

[PATCH] drivers core: Fix oops when driver probe fails

[Filip Schauer]

dma_range_map is freed to early, which might cause an oops when
a driver probe fails.
 Call trace:
  is_free_buddy_page+0xe4/0x1d4
  __free_pages+0x2c/0x88
  dma_free_contiguous+0x64/0x80
  dma_direct_free+0x38/0xb4
  dma_free_attrs+0x88/0xa0
  dmam_release+0x28/0x34
  release_nodes+0x78/0x8c
  devres_release_all+0xa8/0x110
  really_probe+0x118/0x2d0
  __driver_probe_device+0xc8/0xe0
  driver_probe_device+0x54/0xec
  __driver_attach+0xe0/0xf0
  bus_for_each_dev+0x7c/0xc8
  driver_attach+0x30/0x3c
  bus_add_driver+0x17c/0x1c4
  driver_register+0xc0/0xf8
  __platform_driver_register+0x34/0x40
  ...

This issue is introduced by commit d0243bbd5dd3 ("drivers core:
Free dma_range_map when driver probe failed"). It frees
dma_range_map before the call to devres_release_all, which is too
early. The solution is to free dma_range_map only after
devres_release_all.

Fixes: d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed")
Signed-off-by: Filip Schauer <filip@mg6.at>
---
 drivers/base/dd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index daeb9b5763ae..437cd61343b2 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -653,8 +653,6 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	else if (drv->remove)
 		drv->remove(dev);
 probe_failed:
-	kfree(dev->dma_range_map);
-	dev->dma_range_map = NULL;
 	if (dev->bus)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
@@ -662,6 +660,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	device_links_no_driver(dev);
 	devres_release_all(dev);
 	arch_teardown_dma_ops(dev);
+	kfree(dev->dma_range_map);
+	dev->dma_range_map = NULL;
 	driver_sysfs_remove(dev);
 	dev->driver = NULL;
 	dev_set_drvdata(dev, NULL);
-- 
2.25.1

Re: [PATCH] drivers core: Fix oops when driver probe fails

[Greg KH]

On Tue, Jul 27, 2021 at 01:23:11PM +0200, Filip Schauer wrote:
> dma_range_map is freed to early, which might cause an oops when
> a driver probe fails.
>  Call trace:
>   is_free_buddy_page+0xe4/0x1d4
>   __free_pages+0x2c/0x88
>   dma_free_contiguous+0x64/0x80
>   dma_direct_free+0x38/0xb4
>   dma_free_attrs+0x88/0xa0
>   dmam_release+0x28/0x34
>   release_nodes+0x78/0x8c
>   devres_release_all+0xa8/0x110
>   really_probe+0x118/0x2d0
>   __driver_probe_device+0xc8/0xe0
>   driver_probe_device+0x54/0xec
>   __driver_attach+0xe0/0xf0
>   bus_for_each_dev+0x7c/0xc8
>   driver_attach+0x30/0x3c
>   bus_add_driver+0x17c/0x1c4
>   driver_register+0xc0/0xf8
>   __platform_driver_register+0x34/0x40
>   ...
> 
> This issue is introduced by commit d0243bbd5dd3 ("drivers core:
> Free dma_range_map when driver probe failed"). It frees
> dma_range_map before the call to devres_release_all, which is too
> early. The solution is to free dma_range_map only after
> devres_release_all.
> 
> Fixes: d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed")
> Signed-off-by: Filip Schauer <filip@mg6.at>
> ---
>  drivers/base/dd.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Oh, nice catch!  This is a v2, right?  Next time please be explicit :)

thanks,

greg k-h

Re: [PATCH] drivers core: Fix oops when driver probe fails

[Filip Schauer]

On Tue, Jul 27, 2021 at 02:31:10PM +0200, Greg KH wrote:
> On Tue, Jul 27, 2021 at 01:23:11PM +0200, Filip Schauer wrote:
> > dma_range_map is freed to early, which might cause an oops when
> > a driver probe fails.
> >  Call trace:
> >   is_free_buddy_page+0xe4/0x1d4
> >   __free_pages+0x2c/0x88
> >   dma_free_contiguous+0x64/0x80
> >   dma_direct_free+0x38/0xb4
> >   dma_free_attrs+0x88/0xa0
> >   dmam_release+0x28/0x34
> >   release_nodes+0x78/0x8c
> >   devres_release_all+0xa8/0x110
> >   really_probe+0x118/0x2d0
> >   __driver_probe_device+0xc8/0xe0
> >   driver_probe_device+0x54/0xec
> >   __driver_attach+0xe0/0xf0
> >   bus_for_each_dev+0x7c/0xc8
> >   driver_attach+0x30/0x3c
> >   bus_add_driver+0x17c/0x1c4
> >   driver_register+0xc0/0xf8
> >   __platform_driver_register+0x34/0x40
> >   ...
> > 
> > This issue is introduced by commit d0243bbd5dd3 ("drivers core:
> > Free dma_range_map when driver probe failed"). It frees
> > dma_range_map before the call to devres_release_all, which is too
> > early. The solution is to free dma_range_map only after
> > devres_release_all.
> > 
> > Fixes: d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed")
> > Signed-off-by: Filip Schauer <filip@mg6.at>
> > ---
> >  drivers/base/dd.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> Oh, nice catch!  This is a v2, right?  Next time please be explicit :)
> 
> thanks,
> 
> greg k-h
> 

Thank you for adding the patch.
And my bad, this is indeed a PATCH v2.
I didn't know about the patch revisioning convention.
I'll be more explicit next time.

Thanks,

Filip Schauer