| Message ID | 20220118173404.1891800-1-robh@kernel.org |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | of: Check 'of_node_reused' flag on of_match_device() | expand |
| Context | Check | Description |
|---|---|---|
| robh/checkpatch | warning | total: 0 errors, 2 warnings, 8 lines checked |
| robh/dtbs-check | success | |
| robh/dt-meta-schema | success |
On Tue, 18 Jan 2022 11:34:04 -0600, Rob Herring wrote: > Commit 0f153a1b8193 ("usb: chipidea: Set the DT node on the child > device") caused the child device to match on the parent driver > instead of the child's driver since the child's DT node pointer matched. > The worst case result is a loop of the parent driver probing another > instance and creating yet another child device eventually exhausting the > stack. If the child driver happens to match first, then everything works > fine. > > A device sharing the DT node should never do DT based driver matching, > so let's simply check of_node_reused in of_match_device() to prevent > that. > > Fixes: 0f153a1b8193 ("usb: chipidea: Set the DT node on the child device") > Link: https://lore.kernel.org/all/20220114105620.GK18506@ediswmail.ad.cirrus.com/ > Reported-by: Charles Keepax <ckeepax@opensource.cirrus.com> > Cc: Frank Rowand <frowand.list@gmail.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Tony Lindgren <tony@atomide.com> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Peter Chen <peter.chen@nxp.com> > Tested-by: Charles Keepax <ckeepax@opensource.cirrus.com> > Signed-off-by: Rob Herring <robh@kernel.org> > --- > drivers/of/device.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > Applied, thanks!
diff --git a/drivers/of/device.c b/drivers/of/device.c index b0800c260f64..874f031442dc 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -28,7 +28,7 @@ const struct of_device_id *of_match_device(const struct of_device_id *matches, const struct device *dev) { - if ((!matches) || (!dev->of_node)) + if (!matches || !dev->of_node || dev->of_node_reused) return NULL; return of_match_node(matches, dev->of_node); }
Commit 0f153a1b8193 ("usb: chipidea: Set the DT node on the child device") caused the child device to match on the parent driver instead of the child's driver since the child's DT node pointer matched. The worst case result is a loop of the parent driver probing another instance and creating yet another child device eventually exhausting the stack. If the child driver happens to match first, then everything works fine. A device sharing the DT node should never do DT based driver matching, so let's simply check of_node_reused in of_match_device() to prevent that. Fixes: 0f153a1b8193 ("usb: chipidea: Set the DT node on the child device") Link: https://lore.kernel.org/all/20220114105620.GK18506@ediswmail.ad.cirrus.com/ Reported-by: Charles Keepax <ckeepax@opensource.cirrus.com> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Tony Lindgren <tony@atomide.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Peter Chen <peter.chen@nxp.com> Tested-by: Charles Keepax <ckeepax@opensource.cirrus.com> Signed-off-by: Rob Herring <robh@kernel.org> --- drivers/of/device.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)