Commit c78af348836a8d91fddc033ae68bee5dc76241c7
Committed by
Greg Kroah-Hartman
1 parent
971784f012
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>
Showing 1 changed file with 3 additions and 4 deletions Side-by-side Diff
sound/soc/generic/simple-card.c
... | ... | @@ -453,9 +453,8 @@ |
453 | 453 | } |
454 | 454 | |
455 | 455 | /* Decrease the reference count of the device nodes */ |
456 | -static int asoc_simple_card_unref(struct platform_device *pdev) | |
456 | +static int asoc_simple_card_unref(struct snd_soc_card *card) | |
457 | 457 | { |
458 | - struct snd_soc_card *card = platform_get_drvdata(pdev); | |
459 | 458 | struct snd_soc_dai_link *dai_link; |
460 | 459 | struct device_node *np; |
461 | 460 | int num_links; |
... | ... | @@ -562,7 +561,7 @@ |
562 | 561 | return ret; |
563 | 562 | |
564 | 563 | err: |
565 | - asoc_simple_card_unref(pdev); | |
564 | + asoc_simple_card_unref(&priv->snd_card); | |
566 | 565 | return ret; |
567 | 566 | } |
568 | 567 | |
... | ... | @@ -578,7 +577,7 @@ |
578 | 577 | snd_soc_jack_free_gpios(&simple_card_mic_jack, 1, |
579 | 578 | &simple_card_mic_jack_gpio); |
580 | 579 | |
581 | - return asoc_simple_card_unref(pdev); | |
580 | + return asoc_simple_card_unref(card); | |
582 | 581 | } |
583 | 582 | |
584 | 583 | static const struct of_device_id asoc_simple_of_match[] = { |