Unlike recent versions of Linux, barebox represents the dummy regulator as a NULL pointer and regulator API is supposed to anticipate operation on a NULL pointer. When regulator_get_voltage was ported from Linux, this was not taken into consideration, which leads to regulator_get_voltage(NULL) crashing with a NULL pointer dereference. Fix this by returning -EINVAL for dummy regulators. This aligns us with how Linux would behave in this situation. Fixes: 6ee83ce08b24 ("regulator: add regulator_get_voltage() to API") Reported-by: Johannes Zink <j.zink@pengutronix.de> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> --- drivers/regulator/core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 1fb344656f38..472b26f3a0ac 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -574,9 +574,14 @@ EXPORT_SYMBOL_GPL(regulator_bulk_free); int regulator_get_voltage(struct regulator *regulator) { - struct regulator_dev *rdev = regulator->ri->rdev; + struct regulator_dev *rdev; int sel, ret; + if (!regulator) + return -EINVAL; + + rdev = regulator->ri->rdev; + if (rdev->desc->ops->get_voltage_sel) { sel = rdev->desc->ops->get_voltage_sel(rdev); if (sel < 0) -- 2.30.2
There is no point in fixing up an empty string into the kernel device tree, yet this can happen when globalvar_add_simple_string() is called for the variable at least once as the function replaces NULL with an allocated empty string. globalvar_add_simple_string() was called unconditionally for of.kernel.add_machine_compatible, which in turn led to always fixing up an empty string as the top-most compatible. Resolve this by having barebox_get_(of_machine_compatible|serial_number) return NULL for the empty string as well. Fixes: 81dd24a0946c ("of: add generic of_prepend_machine_compatible()") Fixes: f6756e9ce6f2 ("common: add $global.serial_number with device tree fixup") Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> --- common/misc.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/common/misc.c b/common/misc.c index 0f6de3e9e5ef..e0e32f47c59d 100644 --- a/common/misc.c +++ b/common/misc.c @@ -191,6 +191,8 @@ void barebox_set_serial_number(const char *__serial_number) const char *barebox_get_serial_number(void) { + if (!serial_number || *serial_number == '\0') + return NULL; return serial_number; } @@ -204,6 +206,8 @@ void barebox_set_of_machine_compatible(const char *__compatible) const char *barebox_get_of_machine_compatible(void) { + if (!of_machine_compatible || *of_machine_compatible == '\0') + return NULL; return of_machine_compatible; } -- 2.30.2
On Mon, Jul 18, 2022 at 01:48:23PM +0200, Ahmad Fatoum wrote: > Unlike recent versions of Linux, barebox represents the dummy regulator > as a NULL pointer and regulator API is supposed to anticipate operation > on a NULL pointer. When regulator_get_voltage was ported from Linux, > this was not taken into consideration, which leads to > regulator_get_voltage(NULL) crashing with a NULL pointer dereference. > > Fix this by returning -EINVAL for dummy regulators. This aligns us with > how Linux would behave in this situation. > > Fixes: 6ee83ce08b24 ("regulator: add regulator_get_voltage() to API") > Reported-by: Johannes Zink <j.zink@pengutronix.de> > Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> > --- > drivers/regulator/core.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) Applied, thanks Sascha > > diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c > index 1fb344656f38..472b26f3a0ac 100644 > --- a/drivers/regulator/core.c > +++ b/drivers/regulator/core.c > @@ -574,9 +574,14 @@ EXPORT_SYMBOL_GPL(regulator_bulk_free); > > int regulator_get_voltage(struct regulator *regulator) > { > - struct regulator_dev *rdev = regulator->ri->rdev; > + struct regulator_dev *rdev; > int sel, ret; > > + if (!regulator) > + return -EINVAL; > + > + rdev = regulator->ri->rdev; > + > if (rdev->desc->ops->get_voltage_sel) { > sel = rdev->desc->ops->get_voltage_sel(rdev); > if (sel < 0) > -- > 2.30.2 > > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |