ALSA: gus: Fix memory leaks at memory allocator error paths

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 does code-refactoring to move the kstrdup()
call itself into snd_gf1_mem_xalloc() and deals with the resource free
in the helper code by itself for fixing those memory leaks.

Suggested-by: Jaroslav Kysela <perex@perex.cz>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20211213132444.22385-2-tiwai@suse.de
Link: https://lore.kernel.org/r/20211213141512.27359-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/isa/gus/gus_mem.c b/sound/isa/gus/gus_mem.c
index 5e3ff31..3e56c01 100644 (file)
--- a/sound/isa/gus/gus_mem.c
+++ b/sound/isa/gus/gus_mem.c
@@ -24,8 +24,9 @@ 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)
+static struct snd_gf1_mem_block *
+snd_gf1_mem_xalloc(struct snd_gf1_mem *alloc, struct snd_gf1_mem_block *block,
+                  const char *name)
 {
        struct snd_gf1_mem_block *pblock, *nblock;
 
@@ -33,6 +34,12 @@ static struct snd_gf1_mem_block *snd_gf1_mem_xalloc(struct snd_gf1_mem * alloc,
        if (nblock == NULL)
                return NULL;
        *nblock = *block;
+       nblock->name = kstrdup(name, GFP_KERNEL);
+       if (!nblock->name) {
+               kfree(nblock);
+               return NULL;
+       }
+
        pblock = alloc->first;
        while (pblock) {
                if (pblock->ptr > nblock->ptr) {
@@ -198,12 +205,7 @@ 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);
-       if (block.name == NULL) {
-               snd_gf1_mem_lock(alloc, 1);
-               return NULL;
-       }
-       nblock = snd_gf1_mem_xalloc(alloc, &block);
+       nblock = snd_gf1_mem_xalloc(alloc, &block, name);
        snd_gf1_mem_lock(alloc, 1);
        return nblock;
 }
@@ -240,14 +242,12 @@ 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 (block.name == NULL || snd_gf1_mem_xalloc(alloc, &block) == NULL)
+               if (!snd_gf1_mem_xalloc(alloc, &block, "InterWave LFOs"))
                        return -ENOMEM;
        }
        block.ptr = gus->gf1.default_voice_address;
        block.size = 4;
-       block.name = kstrdup("Voice default (NULL's)", GFP_KERNEL);
-       if (block.name == NULL || snd_gf1_mem_xalloc(alloc, &block) == NULL)
+       if (!snd_gf1_mem_xalloc(alloc, &block, "Voice default (NULL's)"))
                return -ENOMEM;
 #ifdef CONFIG_SND_DEBUG
        snd_card_ro_proc_new(gus->card, "gusmem", gus, snd_gf1_mem_info_read);