Re: [PATCH 2/2] ALSA: gus: Fix memory leaks at error paths in memory allocations

[Jaroslav Kysela <perex@xxxxxxxx>]

On 13. 12. 21 14:24, Takashi Iwai wrote:
> When snd_gf1_mem_xalloc() returns NULL, the current code still leaves
> the formerly allocated block.name string but returns an error
> immediately.  This patch covers the all callers to deal with the
> release of leftover name strings in the error paths.
>
> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>

It may be easier to pass the name to snd_gf1_mem_xalloc() - the code flow is more readable:

diff --git a/sound/isa/gus/gus_mem.c b/sound/isa/gus/gus_mem.c
index ff9480f249fe..cd087267b3ea 100644
--- a/sound/isa/gus/gus_mem.c
+++ b/sound/isa/gus/gus_mem.c
@@ -25,14 +25,22 @@ void snd_gf1_mem_lock(struct snd_gf1_mem * alloc, int xup)
 }
 
 static struct snd_gf1_mem_block *snd_gf1_mem_xalloc(struct snd_gf1_mem * alloc,
-					       struct snd_gf1_mem_block * block)
+					       struct snd_gf1_mem_block * block,
+					       const char * _name)
 {
 	struct snd_gf1_mem_block *pblock, *nblock;
+	char *name;
 
+	name = kstrdup(_name, GFP_KERNEL);
+	if (name == NULL)
+		return NULL
 	nblock = kmalloc(sizeof(struct snd_gf1_mem_block), GFP_KERNEL);
-	if (nblock == NULL)
+	if (nblock == NULL) {
+		kfree(name);
 		return NULL;
+	}
 	*nblock = *block;
+	nblock->name = name;
 	pblock = alloc->first;
 	while (pblock) {
 		if (pblock->ptr > nblock->ptr) {
@@ -198,8 +206,7 @@ struct snd_gf1_mem_block *snd_gf1_mem_alloc(struct snd_gf1_mem * alloc, int owne
 	if (share_id != NULL)
 		memcpy(&block.share_id, share_id, sizeof(block.share_id));
 	block.owner = owner;
-	block.name = kstrdup(name, GFP_KERNEL);
-	nblock = snd_gf1_mem_xalloc(alloc, &block);
+	nblock = snd_gf1_mem_xalloc(alloc, &block, name);
 	snd_gf1_mem_lock(alloc, 1);
 	return nblock;
 }
@@ -236,14 +243,12 @@ int snd_gf1_mem_init(struct snd_gus_card * gus)
 	if (gus->gf1.enh_mode) {
 		block.ptr = 0;
 		block.size = 1024;
-		block.name = kstrdup("InterWave LFOs", GFP_KERNEL);
-		if (snd_gf1_mem_xalloc(alloc, &block) == NULL)
+		if (snd_gf1_mem_xalloc(alloc, &block, "InterWave LFOs") == 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 (snd_gf1_mem_xalloc(alloc, &block, "Voice default (NULL's)") == NULL)
 		return -ENOMEM;
 #ifdef CONFIG_SND_DEBUG
 	snd_card_ro_proc_new(gus->card, "gusmem", gus, snd_gf1_mem_info_read);

						Jaroslav

--
Jaroslav Kysela <perex@xxxxxxxx>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.