diff options
| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2015-01-13 21:03:37 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-02-05 22:36:02 -0800 |
| commit | c78af348836a8d91fddc033ae68bee5dc76241c7 (patch) | |
| tree | bf7c1873b7706ab0b102f770cc445c8c8bdc658d /sound | |
| parent | 971784f01272ee66ad16d01837203a701f5bbcab (diff) | |
ASoC: simple-card: Fix crash in asoc_simple_card_unref()
commit 7ddfdb5c5a5b51bdd2cb749d8341d763b079d520 upstream.
If asoc_simple_card_probe() fails, asoc_simple_card_unref() may be
called before dev_set_drvdata(), causing a NULL pointer dereference in
asoc_simple_card_unref():
Unable to handle kernel NULL pointer dereference at virtual address 000000d4
...
PC is at asoc_simple_card_unref+0x14/0x48
LR is at asoc_simple_card_probe+0x3d4/0x40c
This typically happens because asoc_simple_card_parse_of() returns
-EPROBE_DEFER, but other failure modes are possible.
devm_snd_soc_register_card()/snd_soc_register_card() may fail either
before or after dev_set_drvdata().
Pass a snd_soc_card pointer instead of a platform_device pointer to
asoc_simple_card_unref() to fix this.
Note that if CONFIG_OF_DYNAMIC=n, of_node_put() is a dummy, and gcc may
optimize away the loop over card->dai_link, never actually dereferencing
card, and thus avoiding the crash...
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Fixes: e512e001dafa54e5 ("ASoC: simple-card: Fix the reference count of device nodes")
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/soc/generic/simple-card.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c index d1b7293c133e..c6a6693bbfc9 100644 --- a/sound/soc/generic/simple-card.c +++ b/sound/soc/generic/simple-card.c @@ -453,9 +453,8 @@ static int asoc_simple_card_parse_of(struct device_node *node, } /* Decrease the reference count of the device nodes */ -static int asoc_simple_card_unref(struct platform_device *pdev) +static int asoc_simple_card_unref(struct snd_soc_card *card) { - struct snd_soc_card *card = platform_get_drvdata(pdev); struct snd_soc_dai_link *dai_link; struct device_node *np; int num_links; @@ -562,7 +561,7 @@ static int asoc_simple_card_probe(struct platform_device *pdev) return ret; err: - asoc_simple_card_unref(pdev); + asoc_simple_card_unref(&priv->snd_card); return ret; } @@ -578,7 +577,7 @@ static int asoc_simple_card_remove(struct platform_device *pdev) snd_soc_jack_free_gpios(&simple_card_mic_jack, 1, &simple_card_mic_jack_gpio); - return asoc_simple_card_unref(pdev); + return asoc_simple_card_unref(card); } static const struct of_device_id asoc_simple_of_match[] = { |