Messages in this thread | | | Subject | Re: [PATCH] ASoC: samsung: i2s: Null pointer dereference on samsung_i2s_remove | From | Sylwester Nawrocki <> | Date | Thu, 10 Aug 2017 18:23:48 +0200 |
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On 08/10/2017 05:56 PM, Anton Vasilyev wrote: > If (quirks & QUIRK_SEC_DAI == 0) then samsung_i2s_probe() doesn't allocate > sec_dai and pri_dai->sec_dai remains Null, but samsung_i2s_remove() > permorms pri_dai->sec_dai dereference in any case.
s/permorms/performs
> The patch adds sec_dai check on Null before derefence at > samsung_i2s_remove(). > > Found by Linux Driver Verification project (linuxtesting.org). > > Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru> > --- > sound/soc/samsung/i2s.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/sound/soc/samsung/i2s.c b/sound/soc/samsung/i2s.c > index af3ba4d..6beeea8 100644 > --- a/sound/soc/samsung/i2s.c > +++ b/sound/soc/samsung/i2s.c > @@ -1382,7 +1382,8 @@ static int samsung_i2s_remove(struct platform_device *pdev) > sec_dai = pri_dai->sec_dai; > > pri_dai->sec_dai = NULL; > - sec_dai->pri_dai = NULL;
Thanks for the patch. AFAICS above 4 lines could be removed altogether since pri_dai and sec_dai is being allocated with devm_kzalloc(). So initializing in remove() is meaningless as afterwards the data will not be used any more. The memory will be just freed by the devres code.
> + if (sec_dai) > + sec_dai->pri_dai = NULL;
-- Regards, Sylwester
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