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authorGeert Uytterhoeven <geert+renesas@glider.be>2015-01-13 21:03:37 +0100
committerMark Brown <broonie@kernel.org>2015-01-14 17:16:37 +0000
commit7ddfdb5c5a5b51bdd2cb749d8341d763b079d520 (patch)
tree1bf9ac1cc99728ca42900fffe5b7d50daabd95ad /sound/soc/generic
parent97bf6af1f928216fd6c5a66e8a57bfa95a659672 (diff)
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ASoC: simple-card: Fix crash in asoc_simple_card_unref()
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> Cc: stable@vger.kernel.org
Diffstat (limited to 'sound/soc/generic')
-rw-r--r--sound/soc/generic/simple-card.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c
index fb9240fdc9b7..7fe3009b1c43 100644
--- a/sound/soc/generic/simple-card.c
+++ b/sound/soc/generic/simple-card.c
@@ -452,9 +452,8 @@ 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;
int num_links;
@@ -556,7 +555,7 @@ 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;
}
@@ -572,7 +571,7 @@ 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[] = {