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| author | Xiaomeng Tong <xiam0nd.tong@gmail.com> | 2022-03-27 14:08:22 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-20 09:06:29 +0200 |
| commit | d2eeab0e4ad468e1517e01144f4bfb0c8f1cc4a9 (patch) | |
| tree | 72aec1480218fe7eeab58429ac73541d2beca087 /sound | |
| parent | 402ba9106760da09c9058a8c4f377ed3f5a1f8ab (diff) | |
| download | linux-rt-d2eeab0e4ad468e1517e01144f4bfb0c8f1cc4a9.tar.gz | |
ALSA: cs4236: fix an incorrect NULL check on list iterator
commit 0112f822f8a6d8039c94e0bc9b264d7ffc5d4704 upstream.
The bug is here:
err = snd_card_cs423x_pnp(dev, card->private_data, pdev, cdev);
The list iterator value 'cdev' will *always* be set and non-NULL
by list_for_each_entry(), so it is incorrect to assume that the
iterator value will be NULL if the list is empty or no element
is found.
To fix the bug, use a new variable 'iter' as the list iterator,
while use the original variable 'cdev' as a dedicated pointer
to point to the found element. And snd_card_cs423x_pnp() itself
has NULL check for cdev.
Cc: stable@vger.kernel.org
Fixes: c2b73d1458014 ("ALSA: cs4236: cs4232 and cs4236 driver merge to solve PnP BIOS detection")
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Link: https://lore.kernel.org/r/20220327060822.4735-1-xiam0nd.tong@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/isa/cs423x/cs4236.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/sound/isa/cs423x/cs4236.c b/sound/isa/cs423x/cs4236.c index c67d379cb6d6..9d4a2c66ea16 100644 --- a/sound/isa/cs423x/cs4236.c +++ b/sound/isa/cs423x/cs4236.c @@ -557,7 +557,7 @@ static int snd_cs423x_pnpbios_detect(struct pnp_dev *pdev, static int dev; int err; struct snd_card *card; - struct pnp_dev *cdev; + struct pnp_dev *cdev, *iter; char cid[PNP_ID_LEN]; if (pnp_device_is_isapnp(pdev)) @@ -573,9 +573,11 @@ static int snd_cs423x_pnpbios_detect(struct pnp_dev *pdev, strcpy(cid, pdev->id[0].id); cid[5] = '1'; cdev = NULL; - list_for_each_entry(cdev, &(pdev->protocol->devices), protocol_list) { - if (!strcmp(cdev->id[0].id, cid)) + list_for_each_entry(iter, &(pdev->protocol->devices), protocol_list) { + if (!strcmp(iter->id[0].id, cid)) { + cdev = iter; break; + } } err = snd_cs423x_card_new(&pdev->dev, dev, &card); if (err < 0) |