Messages in this thread | | | Date | Sat, 18 Feb 2012 21:37:18 +0800 | Subject | Re: linux-next: dock_link_device is oopsy | From | Hillf Danton <> |
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On Sat, Feb 18, 2012 at 9:26 PM, Holger Macht <holger@homac.de> wrote: > On Sa 18. Feb - 21:05:18, Hillf Danton wrote: >> On Sat, Feb 18, 2012 at 7:14 PM, Holger Macht <holger@homac.de> wrote: >> > So how about that? >> > >> > acpi: Bail out when linking devices and there are no dock stations >> > >> > If dock_station_count is zero, we allocate zero memory and don't check >> > this at future references. So bail out if there are actually no dock >> > stations. >> > >> > Signed-off-by: Holger Macht <holger@homac.de> >> > --- >> > drivers/acpi/dock.c | 19 ++++++++++++++----- >> > 1 files changed, 14 insertions(+), 5 deletions(-) >> > >> > diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c >> > index b5e4142..0b3072c 100644 >> > --- a/drivers/acpi/dock.c >> > +++ b/drivers/acpi/dock.c >> > @@ -281,11 +281,15 @@ EXPORT_SYMBOL_GPL(is_dock_device); >> > */ >> > struct device **dock_link_device(acpi_handle handle) >> > { >> > - struct device *dev = acpi_get_physical_device(handle); >> > + struct device *dev; >> > struct dock_station *dock_station; >> > int ret, dock = 0; >> > struct device **devices; >> > >> > + if (!dock_station_count) >> > + return NULL; >> > + >> > + dev = acpi_get_physical_device(handle); >> > devices = kmalloc(dock_station_count * sizeof(struct device *), >> > GFP_KERNEL); >> > >> > @@ -320,12 +324,17 @@ EXPORT_SYMBOL_GPL(dock_link_device); >> > */ >> > struct device **dock_unlink_device(acpi_handle handle) >> > { >> > - struct device *dev = acpi_get_physical_device(handle); >> > + struct device *dev; >> > struct dock_station *dock_station; >> > int dock = 0; >> > - struct device **devices = >> > - kmalloc(dock_station_count * sizeof(struct device *), >> > - GFP_KERNEL); >> > + struct device **devices; >> > + >> > + if (!dock_station_count) >> > + return NULL; >> > + >> > + dev = acpi_get_physical_device(handle); >> > + devices = kmalloc(dock_station_count * sizeof(struct device *), >> > + GFP_KERNEL); >> > >> >> If bail out in this way, another patch looks needed to fix up >> mem leakage :-( > > Sorry if I'm a little slow...but where is the leakage? The function > doesn't allocate anything before bailing out in the dock_station_count > check. And the rerun value should be freed by the caller. Please point > me in the right direction. >
Hi Holger
Lets check the following snippet from what you posted,
> @@ -320,12 +324,17 @@ EXPORT_SYMBOL_GPL(dock_link_device); > */ > struct device **dock_unlink_device(acpi_handle handle) > { > - struct device *dev = acpi_get_physical_device(handle); > + struct device *dev; > struct dock_station *dock_station; > int dock = 0; > - struct device **devices = > - kmalloc(dock_station_count * sizeof(struct device *), > - GFP_KERNEL); > + struct device **devices; > + > + if (!dock_station_count) > + return NULL; > + > + dev = acpi_get_physical_device(handle); > + devices = kmalloc(dock_station_count * sizeof(struct device *), > + GFP_KERNEL); > > if (!dev) > return NULL; <=== here return without freeing the newly allocated devices after checking dock_station_count is not zero > -- > 1.7.7 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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