From d0f2ca62e89f3c666d0ec203eaa23b8d965e5443 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 7 Oct 2026 19:25:20 +0200 Subject: [PATCH] ALSA: pcmtest: Fix leak at probe error When an error happens at probe of pcmtest driver before snd_card_register() succeeds, we have to release the card explicitly, but it's not done, leading to a potential memory leak. Also, pcmtest driver manages struct pcmtst object unnecessarily complicatedly by a dynamic allocation and release. This patch fixes and cleans up the resource management: - Use card's private_data allocation for struct sndpcmtst at the card creation, which is released automatically together with the card - Since the allocation of pcmtest is gone, snd_pcmtst_create() is rather pointless, so just directly calling snd_pcmtst_new_pcm() - Use the new auto-clean mechanism to handle the error case at probe. - Many release handlers became superfluous and dropped In the end we got a good amount of code reduction. Fixes: 315a3d57c64c ("ALSA: Implement the new Virtual PCM Test Driver") Reported-by: Sashiko Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20261007172533.14667-3-tiwai@suse.de --- sound/drivers/pcmtest.c | 66 +++++++---------------------------------- 1 file changed, 10 insertions(+), 56 deletions(-) diff --git a/sound/drivers/pcmtest.c b/sound/drivers/pcmtest.c index fea9580593e6..b4e333b4c438 100644 --- a/sound/drivers/pcmtest.c +++ b/sound/drivers/pcmtest.c @@ -446,20 +446,6 @@ static snd_pcm_uframes_t snd_pcmtst_pcm_pointer(struct snd_pcm_substream *substr return bytes_to_frames(substream->runtime, v_iter->buf_pos); } -static int snd_pcmtst_free(struct pcmtst *pcmtst) -{ - if (!pcmtst) - return 0; - kfree(pcmtst); - return 0; -} - -// These callbacks are required, but empty - all freeing occurs in pdev_remove -static int snd_pcmtst_dev_free(struct snd_device *device) -{ - return 0; -} - static void pcmtst_pdev_release(struct device *dev) { } @@ -563,40 +549,9 @@ static int snd_pcmtst_new_pcm(struct pcmtst *pcmtst) return err; } -static int snd_pcmtst_create(struct snd_card *card, struct platform_device *pdev, - struct pcmtst **r_pcmtst) -{ - struct pcmtst *pcmtst; - int err; - static const struct snd_device_ops ops = { - .dev_free = snd_pcmtst_dev_free, - }; - - pcmtst = kzalloc_obj(*pcmtst); - if (!pcmtst) - return -ENOMEM; - pcmtst->card = card; - pcmtst->pdev = pdev; - - err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, pcmtst, &ops); - if (err < 0) - goto _err_free_chip; - - err = snd_pcmtst_new_pcm(pcmtst); - if (err < 0) - goto _err_free_chip; - - *r_pcmtst = pcmtst; - return 0; - -_err_free_chip: - snd_pcmtst_free(pcmtst); - return err; -} - static int pcmtst_probe(struct platform_device *pdev) { - struct snd_card *card; + struct snd_card *card __free(snd_card_free) = NULL; struct pcmtst *pcmtst; int err; @@ -604,10 +559,16 @@ static int pcmtst_probe(struct platform_device *pdev) if (err) return err; - err = snd_devm_card_new(&pdev->dev, index, id, THIS_MODULE, 0, &card); + err = snd_devm_card_new(&pdev->dev, index, id, THIS_MODULE, + sizeof(*pcmtst), &card); if (err < 0) return err; - err = snd_pcmtst_create(card, pdev, &pcmtst); + + pcmtst = card->private_data; + pcmtst->card = card; + pcmtst->pdev = pdev; + + err = snd_pcmtst_new_pcm(pcmtst); if (err < 0) return err; @@ -620,17 +581,11 @@ static int pcmtst_probe(struct platform_device *pdev) return err; platform_set_drvdata(pdev, pcmtst); + card = NULL; /* probe succeeded, don't release as error */ return 0; } -static void pdev_remove(struct platform_device *pdev) -{ - struct pcmtst *pcmtst = platform_get_drvdata(pdev); - - snd_pcmtst_free(pcmtst); -} - static struct platform_device pcmtst_pdev = { .name = "pcmtest", .dev.release = pcmtst_pdev_release, @@ -638,7 +593,6 @@ static struct platform_device pcmtst_pdev = { static struct platform_driver pcmtst_pdrv = { .probe = pcmtst_probe, - .remove = pdev_remove, .driver = { .name = "pcmtest", },