ALSA: sound/isa/gus: check the return value of kstrdup()

kstrdup() returns NULL when some internal memory errors happen, it is
better to check the return value of it. Otherwise, we may not to be able
to catch some memory errors in time.
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Link: https://lore.kernel.org/r/tencent_1E3950293AC22395ACFE99404C985D738309@qq.comSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/isa/gus/gus_mem.c

@@ -199,6 +199,10 @@ struct snd_gf1_mem_block *snd_gf1_mem_alloc(struct snd_gf1_mem * alloc, int owne
 		memcpy(&block.share_id, share_id, sizeof(block.share_id));
 	block.owner = owner;
 	block.name = kstrdup(name, GFP_KERNEL);
+	if (block.name == NULL) {
+		snd_gf1_mem_lock(alloc, 1);
+		return NULL;
+	}
 	nblock = snd_gf1_mem_xalloc(alloc, &block);
 	snd_gf1_mem_lock(alloc, 1);
 	return nblock;
@@ -237,13 +241,13 @@ int snd_gf1_mem_init(struct snd_gus_card * gus)
 		block.ptr = 0;
 		block.size = 1024;
 		block.name = kstrdup("InterWave LFOs", GFP_KERNEL);
-		if (snd_gf1_mem_xalloc(alloc, &block) == NULL)
+		if (block.name == NULL || snd_gf1_mem_xalloc(alloc, &block) == NULL)
 			return -ENOMEM;
 	}
 	block.ptr = gus->gf1.default_voice_address;
 	block.size = 4;
 	block.name = kstrdup("Voice default (NULL's)", GFP_KERNEL);
-	if (snd_gf1_mem_xalloc(alloc, &block) == NULL)
+	if (block.name == NULL || snd_gf1_mem_xalloc(alloc, &block) == NULL)
 		return -ENOMEM;
 #ifdef CONFIG_SND_DEBUG
 	snd_card_ro_proc_new(gus->card, "gusmem", gus, snd_gf1_mem_info_read);