Commit 1f0dd544 authored Jun 11, 2020 by Takashi Iwai Committed by Yang Yingliang Jun 11, 2020

ALSA: proc: Avoid possible leaks of snd_info_entry objects



mainline inclusion
from mainline-v5.1-rc1
commit 3a554371
category: bugfix
bugzilla: 34614
CVE: NA

-----------------------------------------------

This patch changes the parent pointer assignment of snd_info_entry
object to be always non-NULL.  More specifically,check the parent
argument in snd_info_create_module_entry() & co, and assign
snd_proc_root if NULL is passed there.

This assures that the proc object is always freed when the root is
freed, so avoid possible memory leaks.  For example, some error paths
(e.g. snd_info_register() error at snd_minor_info_init()) may leave
snd_info_entry object although the proc file itself is freed.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>

parent b1eabe98

sound/core/info.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -744,7 +744,11 @@ struct snd_info_entry snd_info_create_module_entry(struct module module,
		const char *name,
		struct snd_info_entry *parent)
		{
		struct snd_info_entry *entry = snd_info_create_entry(name, parent);
		struct snd_info_entry *entry;

		if (!parent)
		parent = snd_proc_root;
		entry = snd_info_create_entry(name, parent);
		if (entry)
		entry->module = module;
		return entry;
		@@ -765,7 +769,11 @@ struct snd_info_entry snd_info_create_card_entry(struct snd_card card,
		const char *name,
		struct snd_info_entry * parent)
		{
		struct snd_info_entry *entry = snd_info_create_entry(name, parent);
		struct snd_info_entry *entry;

		if (!parent)
		parent = card->proc_root;
		entry = snd_info_create_entry(name, parent);
		if (entry) {
		entry->module = card->module;
		entry->card = card;