Messages in this thread | | | Date | Tue, 1 Jul 2014 08:55:13 +0200 (CEST) | From | Jiri Kosina <> | Subject | Re: [PATCH v2] hid-appleir: Fix kernel panic due to null pointer |
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On Tue, 1 Jul 2014, Mateusz Guzik wrote:
> > > Fixes a null pointer in appleir_input_configured due to reading > > > into wrong size array. Changed the variable to input_dev->keycodemax. > > > > This is a stale changelog from the previous buggy version. > > > > > Signed-off-by: Nicholas Krause <xerofoify@gmail.com> > > > --- > > > drivers/hid/hid-appleir.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/hid/hid-appleir.c b/drivers/hid/hid-appleir.c > > > index 0e6a42d..cc02df4 100644 > > > --- a/drivers/hid/hid-appleir.c > > > +++ b/drivers/hid/hid-appleir.c > > > @@ -272,7 +272,7 @@ static void appleir_input_configured(struct hid_device *hid, > > > input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_REP); > > > > > > memcpy(appleir->keymap, appleir_key_table, sizeof(appleir->keymap)); > > > - for (i = 0; i < ARRAY_SIZE(appleir_key_table); i++) > > > + for (i = 0; i < appleir->keymap; i++) > > > > This is wrong. appleir->keymap is an array, and you want to count its > > elements. > > > > But where the claim of 'null pointer' is coming from (or reading/writing > past the array for that matter)? > > Replacing appleir_key_table with appleir->keymap is a noop anyway > because: > unsigned short keymap[ARRAY_SIZE(appleir_key_table)];
It's not really equivalent. ARRAY_SIZE counts the number of short-sized elements, sizeof() counts the number of bytes that fit into the data structure (which is twice as much, as sizeof(unsigned short) == 2).
-- Jiri Kosina SUSE Labs
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