Messages in this thread | | | From | Shuah Khan <> | Subject | [PATCH 0/2] power_supply: Fix Oops from NULL pointer dereference from wakeup_source_activate | Date | Wed, 20 Nov 2013 18:40:48 -0700 |
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power_supply_register() calls device_init_wakeup() to register a wakeup source before initializing dev_name. As a result, device_wakeup_enable() end up registering wakeup source with a null name when wakeup_source_register() gets called with dev_name(dev) which is null at the time.
device_wakeup_enable() uses dev_name(dev) as the wakeup source name. When it gets called with a device with its name not yet set, ws structure with ws->name = NULL gets created.
When kernel is booted with wakeup_source_activate enabled, it will panic when the trace point code tries to dereference ws->name. Registering a a wakeup source without a name should be possible.
This patch series fixes power_supply_register() to initialize the device name prior to calling device_init_wakeup() and fixes wakeup_source_activate tracepoint to check for null name and handle it gracefully by just using "(no name)" as the name string for the source.
These two patches are not dependent, I left them as a series since the original discussion started the fixes grouped in a series.
power_supply patch - no changes since series patch v1, other than including Acked-by from Greg and Anton. Also added stable tag.
Second patch now is the fix to tracepoint code. This fix is definitely better than adding WARN_ON to device_wakeup_enable(). It removes the dependency between these two patches.
These patches can be applied independently with no ill effects. I included the trace for the wakeup_source_activate trace output in the changelogs for both patches.
Shuah Khan (2): power_supply: Fix Oops from NULL pointer dereference from wakeup_source_activate PM: Fix Oops from NULL pointer dereference in wakeup_source_activate
drivers/power/power_supply_core.c | 12 ++++++------ include/trace/events/power.h | 6 ++++-- 2 files changed, 10 insertions(+), 8 deletions(-)
-- 1.8.3.2
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