Closed Bug 767370 Opened 7 years ago Closed 7 years ago

Uninitialised value use in nsIDOMKeyEvent_GetCharCode

Categories

(Core :: DOM: Events, defect)

x86_64
Linux
defect
Not set

Tracking

()

RESOLVED FIXED
mozilla16

People

(Reporter: jseward, Assigned: jseward)

Details

Attachments

(1 file, 1 obsolete file)

TEST_PATH=content/events/test/test_dom_keyboard_event.html

nsIDOMKeyEvent_GetCharCode(JSContext*, JS::Handle<JSObject*>,
JS::Handle<long>, JS::Value*) has this

    PRUint32 result;
    rv = self->GetCharCode(&result);
    if (NS_FAILED(rv))
        return xpc_qsThrowGetterSetterFailed(cx, rv, JSVAL_TO_OBJECT(*vp), id);

GetCharCode can return a non-NS_FAILED |rv| without assigning anything
to |result|.  The resulting uninitialised values get copied far and
wide throughout the system and result in dozens of error reports from
Valgrind.  The first one is shown below.

Conditional jump or move depends on uninitialised value(s)
   at 0x6BF5B74: nsIDOMKeyEvent_GetCharCode(JSContext*, JS::Handle<JSObject*>, JS::Handle<long>, JS::Value*) (jsapi.h:1849)
   by 0x7489207: js::baseops::GetProperty(JSContext*, JS::Handle<JSObject*>, JS::Handle<JSObject*>, JS::Handle<long>, JS::Value*) (jscntxtinlines.h:444)
   by 0x7471E9B: js::Interpret(JSContext*, js::StackFrame*, js::InterpMode) (jsobjinlines.h:162)
   by 0x7473BCE: js::RunScript(JSContext*, JSScript*, js::StackFrame*) (jsinterp.cpp:267)
   by 0x74741A8: js::InvokeKernel(JSContext*, js::CallArgs, js::MaybeConstruct) (jsinterp.cpp:322)
   by 0x74746FA: js::Invoke(JSContext*, JS::Value const&, JS::Value const&, unsigned int, JS::Value*, JS::Value*) (jsinterp.h:100)
   by 0x7403EFD: JS_CallFunctionValue (jsapi.cpp:5489)
   by 0x689F2C9: nsJSContext::CallEventHandler(nsISupports*, JSObject*, JSObject*, nsIArray*, nsIVariant**) [clone .part.80] (nsJSEnvironment.cpp:1910)
   by 0x68BF291: nsGlobalWindow::RunTimeoutHandler(nsTimeout*, nsIScriptContext*) (nsGlobalWindow.cpp:9066)
   by 0x68BFF7F: nsGlobalWindow::RunTimeout(nsTimeout*) (nsGlobalWindow.cpp:9320)
   by 0x68C0088: nsGlobalWindow::TimerCallback(nsITimer*, void*) (nsGlobalWindow.cpp:9591)
   by 0x70BB351: nsTimerImpl::Fire() (nsTimerImpl.cpp:473)
 Uninitialised value was created by a stack allocation
   at 0x6BF5AC0: nsIDOMKeyEvent_GetCharCode(JSContext*, JS::Handle<JSObject*>, JS::Handle<long>, JS::Value*) (dom_quickstubs.cpp:10965)
Attached patch fix (obsolete) — Splinter Review
Attachment #635733 - Flags: review?(peterv)
Attachment #635733 - Flags: review?(peterv) → review+
Keywords: checkin-needed
I'll check the patch in for you, but could you please export a proper hg patch with attribution, comment message, etc.?
Clearing c-n while the patch gets tidied.
Keywords: checkin-needed
Attachment #635733 - Attachment is obsolete: true
https://hg.mozilla.org/integration/mozilla-inbound/rev/31cf3f1603d7
Assignee: nobody → jseward
Status: NEW → ASSIGNED
https://hg.mozilla.org/mozilla-central/rev/31cf3f1603d7
Status: ASSIGNED → RESOLVED
Closed: 7 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla16
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