* [PATCH] usb: ulpi: Add missing of_node_get() in ulpi_of_register()
@ 2017-11-11 1:43 Stephen Boyd
2017-11-11 15:25 ` Johan Hovold
2017-11-11 15:31 ` [PATCH] USB: ulpi: fix bus-node lookup Johan Hovold
0 siblings, 2 replies; 3+ messages in thread
From: Stephen Boyd @ 2017-11-11 1:43 UTC (permalink / raw)
To: Heikki Krogerus, Greg Kroah-Hartman
Cc: linux-kernel, linux-arm-msm, linux-usb, Rob Clark, Peter Robinson
In ulpi_of_register() we call of_find_node_by_name() which
unconditionally calls of_node_put() on the 'from' argument. We
haven't called of_node_get() though, so we've put the node once
without getting it first. Add the of_node_get() call so that
things are properly balanced.
Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT")
Reported-by: Peter Robinson <pbrobinson@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
drivers/usb/common/ulpi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
index 4aa5195db8ea..59e05eff76f9 100644
--- a/drivers/usb/common/ulpi.c
+++ b/drivers/usb/common/ulpi.c
@@ -182,9 +182,9 @@ static int ulpi_of_register(struct ulpi *ulpi)
/* Find a ulpi bus underneath the parent or the grandparent */
parent = ulpi->dev.parent;
- if (parent->of_node)
+ if (of_node_get(parent->of_node))
np = of_find_node_by_name(parent->of_node, "ulpi");
- else if (parent->parent && parent->parent->of_node)
+ else if (parent->parent && of_node_get(parent->parent->of_node))
np = of_find_node_by_name(parent->parent->of_node, "ulpi");
if (!np)
return 0;
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] usb: ulpi: Add missing of_node_get() in ulpi_of_register()
2017-11-11 1:43 [PATCH] usb: ulpi: Add missing of_node_get() in ulpi_of_register() Stephen Boyd
@ 2017-11-11 15:25 ` Johan Hovold
2017-11-11 15:31 ` [PATCH] USB: ulpi: fix bus-node lookup Johan Hovold
1 sibling, 0 replies; 3+ messages in thread
From: Johan Hovold @ 2017-11-11 15:25 UTC (permalink / raw)
To: Stephen Boyd
Cc: Heikki Krogerus, Greg Kroah-Hartman, linux-kernel, linux-arm-msm,
linux-usb, Rob Clark, Peter Robinson
On Fri, Nov 10, 2017 at 05:43:00PM -0800, Stephen Boyd wrote:
> In ulpi_of_register() we call of_find_node_by_name() which
> unconditionally calls of_node_put() on the 'from' argument. We
> haven't called of_node_get() though, so we've put the node once
> without getting it first. Add the of_node_get() call so that
> things are properly balanced.
>
> Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT")
> Reported-by: Peter Robinson <pbrobinson@gmail.com>
> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
> ---
> drivers/usb/common/ulpi.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
> index 4aa5195db8ea..59e05eff76f9 100644
> --- a/drivers/usb/common/ulpi.c
> +++ b/drivers/usb/common/ulpi.c
> @@ -182,9 +182,9 @@ static int ulpi_of_register(struct ulpi *ulpi)
>
> /* Find a ulpi bus underneath the parent or the grandparent */
> parent = ulpi->dev.parent;
> - if (parent->of_node)
> + if (of_node_get(parent->of_node))
> np = of_find_node_by_name(parent->of_node, "ulpi");
> - else if (parent->parent && parent->parent->of_node)
> + else if (parent->parent && of_node_get(parent->parent->of_node))
> np = of_find_node_by_name(parent->parent->of_node, "ulpi");
I'm afraid this isn't the right fix; the code shouldn't have been using
of_find_node_by_name() in the first place as that function searches the
whole device tree depth-first starting at the parent (or grand parent),
which could end up matching an unrelated node.
of_get_child_by_name() is the helper to use for such lookups instead.
Turns out we have a few other driver with similar bugs. I've started
fixing a few of them that'll be sending out per subsystem.
I'll post a fix for this one as follow up to this mail meanwhile.
Thanks,
Johan
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH] USB: ulpi: fix bus-node lookup
2017-11-11 1:43 [PATCH] usb: ulpi: Add missing of_node_get() in ulpi_of_register() Stephen Boyd
2017-11-11 15:25 ` Johan Hovold
@ 2017-11-11 15:31 ` Johan Hovold
1 sibling, 0 replies; 3+ messages in thread
From: Johan Hovold @ 2017-11-11 15:31 UTC (permalink / raw)
To: Heikki Krogerus
Cc: Greg Kroah-Hartman, linux-usb, linux-kernel, linux-arm-msm,
Rob Clark, Peter Robinson, Johan Hovold, stable
Fix bus-node lookup during registration, which ended up searching the whole
device tree depth-first starting at the parent (or grand parent) rather
than just matching on its children.
To make things worse, the parent (or grand-parent) node could end being
prematurely freed as well.
Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT")
Reported-by: Peter Robinson <pbrobinson@gmail.com>
Reported-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: stable <stable@vger.kernel.org> # 4.10
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/usb/common/ulpi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
index 8b351444cc40..9a2ab6751a23 100644
--- a/drivers/usb/common/ulpi.c
+++ b/drivers/usb/common/ulpi.c
@@ -180,9 +180,9 @@ static int ulpi_of_register(struct ulpi *ulpi)
/* Find a ulpi bus underneath the parent or the grandparent */
parent = ulpi->dev.parent;
if (parent->of_node)
- np = of_find_node_by_name(parent->of_node, "ulpi");
+ np = of_get_child_by_name(parent->of_node, "ulpi");
else if (parent->parent && parent->parent->of_node)
- np = of_find_node_by_name(parent->parent->of_node, "ulpi");
+ np = of_get_child_by_name(parent->parent->of_node, "ulpi");
if (!np)
return 0;
--
2.15.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2017-11-11 1:43 [PATCH] usb: ulpi: Add missing of_node_get() in ulpi_of_register() Stephen Boyd
2017-11-11 15:25 ` Johan Hovold
2017-11-11 15:31 ` [PATCH] USB: ulpi: fix bus-node lookup Johan Hovold
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