The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x e11c5c13ce0ab2325d38fe63500be1dd88b81e38 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025121601-unpopular-opulently-2ac5@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From e11c5c13ce0ab2325d38fe63500be1dd88b81e38 Mon Sep 17 00:00:00 2001 From: Junrui Luo moonafterrain@outlook.com Date: Thu, 6 Nov 2025 10:24:57 +0800 Subject: [PATCH] ALSA: wavefront: Clear substream pointers on close

Clear substream pointers in close functions to avoid leaving dangling pointers, helping to improve code safety and prevents potential issues.

Reported-by: Yuhao Jiang danisjiang@gmail.com Reported-by: Junrui Luo moonafterrain@outlook.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Junrui Luo moonafterrain@outlook.com Link: https://patch.msgid.link/SYBPR01MB7881DF762CAB45EE42F6D812AFC2A@SYBPR01MB788... Signed-off-by: Takashi Iwai tiwai@suse.de

diff --git a/sound/isa/wavefront/wavefront_midi.c b/sound/isa/wavefront/wavefront_midi.c index 1250ecba659a..69d87c4cafae 100644 --- a/sound/isa/wavefront/wavefront_midi.c +++ b/sound/isa/wavefront/wavefront_midi.c @@ -278,6 +278,7 @@ static int snd_wavefront_midi_input_close(struct snd_rawmidi_substream *substrea return -EIO;

guard(spinlock_irqsave)(&midi->open); + midi->substream_input[mpu] = NULL; midi->mode[mpu] &= ~MPU401_MODE_INPUT;

return 0; @@ -300,6 +301,7 @@ static int snd_wavefront_midi_output_close(struct snd_rawmidi_substream *substre return -EIO;

guard(spinlock_irqsave)(&midi->open); + midi->substream_output[mpu] = NULL; midi->mode[mpu] &= ~MPU401_MODE_OUTPUT; return 0; }