ALSA: emu10k1: fix capture interrupt handler unlinking

commit b09c551c77c7e01dc6e4f3c8bf06b5ffa7b06db5 upstream.

Due to two copy/pastos, closing the MIC or EFX capture device would
make a running ADC capture hang due to unsetting its interrupt handler.
In principle, this would have also allowed dereferencing dangling
pointers, but we're actually rather thorough at disabling and flushing
the ints.

While it may sound like one, this actually wasn't a hypothetical bug:
PortAudio will open a capture stream at startup (and close it right
away) even if not asked to. If the first device is busy, it will just
proceed with the next one ... thus killing a concurrent capture.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20230405201220.2197923-1-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/sound/pci/emu10k1/emupcm.c b/sound/pci/emu10k1/emupcm.c
index ee7e4d46e27beeda5ec20a60c201fc7a44f3c2c6..438d5d41fb4e0fd2e444e3b8eaf002e9412fc7b9 100644 (file)
--- a/sound/pci/emu10k1/emupcm.c
+++ b/sound/pci/emu10k1/emupcm.c
@@ -1251,7 +1251,7 @@ static int snd_emu10k1_capture_mic_close(struct snd_pcm_substream *substream)
 {
        struct snd_emu10k1 *emu = snd_pcm_substream_chip(substream);
 
-       emu->capture_interrupt = NULL;
+       emu->capture_mic_interrupt = NULL;
        emu->pcm_capture_mic_substream = NULL;
        return 0;
 }
@@ -1359,7 +1359,7 @@ static int snd_emu10k1_capture_efx_close(struct snd_pcm_substream *substream)
 {
        struct snd_emu10k1 *emu = snd_pcm_substream_chip(substream);
 
-       emu->capture_interrupt = NULL;
+       emu->capture_efx_interrupt = NULL;
        emu->pcm_capture_efx_substream = NULL;
        return 0;
 }