The patch below does not apply to the 6.12-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-6.12.y git checkout FETCH_HEAD git cherry-pick -x 830988b6cf197e6dcffdfe2008c5738e6c6c3c0f # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2026011238-subduing-rural-1bbc@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 830988b6cf197e6dcffdfe2008c5738e6c6c3c0f Mon Sep 17 00:00:00 2001 From: Haoxiang Li lihaoxiang@isrc.iscas.ac.cn Date: Sat, 20 Dec 2025 00:28:45 +0800 Subject: [PATCH] ALSA: ac97: fix a double free in snd_ac97_controller_register()
If ac97_add_adapter() fails, put_device() is the correct way to drop the device reference. kfree() is not required. Add kfree() if idr_alloc() fails and in ac97_adapter_release() to do the cleanup.
Found by code review.
Fixes: 74426fbff66e ("ALSA: ac97: add an ac97 bus") Cc: stable@vger.kernel.org Signed-off-by: Haoxiang Li lihaoxiang@isrc.iscas.ac.cn Link: https://patch.msgid.link/20251219162845.657525-1-lihaoxiang@isrc.iscas.ac.cn Signed-off-by: Takashi Iwai tiwai@suse.de
diff --git a/sound/ac97/bus.c b/sound/ac97/bus.c index f4254703d29f..bb9b795e0226 100644 --- a/sound/ac97/bus.c +++ b/sound/ac97/bus.c @@ -298,6 +298,7 @@ static void ac97_adapter_release(struct device *dev) idr_remove(&ac97_adapter_idr, ac97_ctrl->nr); dev_dbg(&ac97_ctrl->adap, "adapter unregistered by %s\n", dev_name(ac97_ctrl->parent)); + kfree(ac97_ctrl); }
static const struct device_type ac97_adapter_type = { @@ -319,7 +320,9 @@ static int ac97_add_adapter(struct ac97_controller *ac97_ctrl) ret = device_register(&ac97_ctrl->adap); if (ret) put_device(&ac97_ctrl->adap); - } + } else + kfree(ac97_ctrl); + if (!ret) { list_add(&ac97_ctrl->controllers, &ac97_controllers); dev_dbg(&ac97_ctrl->adap, "adapter registered by %s\n", @@ -361,14 +364,11 @@ struct ac97_controller *snd_ac97_controller_register( ret = ac97_add_adapter(ac97_ctrl);
if (ret) - goto err; + return ERR_PTR(ret); ac97_bus_reset(ac97_ctrl); ac97_bus_scan(ac97_ctrl);
return ac97_ctrl; -err: - kfree(ac97_ctrl); - return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(snd_ac97_controller_register);