From: Haoxiang Li Date: Fri, 19 Dec 2025 16:28:45 +0000 (+0800) Subject: ALSA: ac97: fix a double free in snd_ac97_controller_register() X-Git-Tag: v6.19-rc5~31^2~4 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=830988b6cf197e6dcffdfe2008c5738e6c6c3c0f;p=thirdparty%2Fkernel%2Flinux.git 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 Link: https://patch.msgid.link/20251219162845.657525-1-lihaoxiang@isrc.iscas.ac.cn Signed-off-by: Takashi Iwai --- diff --git a/sound/ac97/bus.c b/sound/ac97/bus.c index f4254703d29f7..bb9b795e02262 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);